| 項目 |
| J |
| J カーブ効果［J-curve effect］ |
| J リーグ［(和) J League］ |
| .j*w |
| JA1 |
| JA2［Japan Agricultural Cooperative］ |
| JAA1［Japan Advertising Association］ |
| JAA2［Japan Aeronautic Association］ |
| JAAF［Japan Amateur Athletic Federation］ |
| JAAS［Japanese Association for American Studies］ |
| JAB［Japan Accreditation Board for Conformity Assessment］ |
| JABA［Japan Amateur Baseball Association］ |
| JABC［Japan Audit Bureau of Circulations］ |
| JACL［Japanese-American Citizens League］ |
| JAEC［Atomic Energy Commission of Japan］ |
| JAERI（ジャエリ）［Japan Atomic Energy Research Institute］ |
| JAF（ジャフ）［Japan Automobile Federation］ |
| JAGDA［Japan Graphic Designers' Association］ |
| JAIDO（ジャイド）［Japan International Development Organization］ |
| JAIWR［Japanese Association of International Women's Rights］ |
| JAL（ジャル）［Japan Airlines］ |
| JALMA（ジャルマ）［Japan Leprosy Mission for Asia］ |
| JAM［Jamaica］ |
| JAMA（ジャマ）［Japan Automobile Manufactures' Association］ |
| JAMFA（ジャンファ）［Japan Medical Foods Association］ |
| JAN［Japanese article number］ |
| JANIC［Japanese NGO Center for International Cooperation］ |
| JAPC［Japan Atomic Power Company］ |
| JAPIC［Japan Project Industry Council］ |
| JAPIO（ジャピオ）［Japan Patent Information Organization］ |
| JARL［Japan Amateur Radio League］ |
| JARO（ジャロ）［Japan Advertising Review Organization］ |
| JAS1［Japan Air System］ |
| JAS2（ジャス）［Japanese Agricultural Standard］ |
| JASA［Japan Amateur Sports Association］ |
| JASDAQ（ジャスダック）［Japan Association of Securities Dealers Automated Quotations］ |
| JASDF［Japan Air Self-Defense Force］ |
| JASRAC（ジャスラック）［Japanese Society for Rights of Authors, Composers and Publishers］ |
| JAST 計画［Joint Advanced Strike Technology Program］ |
| JASW［Japanese Association of Social Workers］ |
| JBA［All Japan Boxing Association］ |
| JBBY［Japanese Board on Books for Young People］ |
| JB Net［Japan Bond Settlement Network Co.,LTD.］ |
| JC［Japan Junior Chamber］ |
| JCA［Japan Consumers' Association］ |
| JCAB［Japan Civil Aviation Bureau］ |
| JCBL［Japan Campaign to Ban Landmines］ |
| JCCI［Japan Chamber of Commerce and Industry］ |
| JCI［Junior Chamber International］ |
| JCP［Japan Communist Party］ |
| JCQHC［Japan Council for Quality Health Care］ |
| JCT［junction］ |
| JD［Japan Air System］ |
| JDB［Japan Development Bank］ |
| JDCA［Japan Data Communications Association］ |
| JDR［Japan Disaster Relief Team］ |
| JED［Jedda, Jiddah］ |
| JEIDA（ジェイダ）［Japan Electronic Industry Development Association］ |
| JESSI （ジェシー）プログラム［Joint European Submicron Silicon Program］ |
| JET［Joint European Torus］ |
| JET（ジェット）プログラム［Japan Exchange and Teaching Program］ |
| JETRO（ジェトロ）［Japan External Trade Organization］ |
| JFA［Japan Football Association］ |
| JFCC［Japan Federation for Culture Collection］ |
| JFK1［John F. Kennedy］ |
| JFK2［John F. Kennedy］ |
| JFL［Japan Football League］ |
| JFPC［Japan Flower Promotion Center］ |
| JGA［Japan Golf Association］ |
| JGOFS［Joint Global Ocean Flux Study］ |
| JGSDF［Japan Ground Self-Defense Force］ |
| JH［Japan Highway］ |
| JIBICO［Japan International Bank and Investment］ |
| JICA（ジャイカ）［Japan International Cooperation Agency］ |
| JICST（ジクスト）［Japan Information Center of Science and Technology］ |
| JIS（ジス）［Japanese Industrial Standard］ |
| JIS コード［JIS code］ |
| JIS マーク［JIS mark］ |
| JIT［just in time］ |
| JJSA［Japan Junior Sports-club Association］ |
| JKC［Japan Kennel Club］ |
| JKCA［Japan-Korea Cultural Association］ |
| JL［Japan Airlines］ |
| JLA［Japan Library Association］ |
| JLC［Japan linear collider］ |
| JLPGA1［Japan Ladies Professional Golfers' Association］ |
| JLPGA2［Japan LP-Gas Association］ |
| JLSL［Japan Ladies Soccer League］ |
| JM［Jamaica］ |
| JMA1［Japan Management Association］ |
| JMA2［Japan Marketing Association］ |
| JMA3［Japan Medical Association］ |
| J/MARC（ジェー-マーク）［Japan MARC］ |
| JMSDF［Japan Maritime Self-Defense Force］ |
| JMTDR［Japan Medical Team for Disaster Relief］ |
| JO［Hashemite Kingdom of Jordan］ |
| JOC［Japan Olympic Committee］ |
| JOCV［Japan Overseas Cooperation Volunteers］ |
| JOIS（ジョイス）［JICST On-line Information System］ |
| JOM［Japan offshore market］ |
| JOR［Hashemite Kingdom of Jordan］ |
| JP［Japan］ |
| JPA1［Japan Pharmaceutical Association］ |
| JPA2［Japan Psychological Association］ |
| JPC［Japan Productivity Center］ |
| JPCERT/CC（ジェイピー サート）［Japan Computer Emergency Response Team/Coordination Center］ |
| JPEG（ジェー-ペグ）［joint photographic expert group］ |
| .jpg［joint photographic expert group］ |
| JPGA［Japan Professional Golfers' Association］ |
| JPN［Japan］ |
| JPNIC［Japan Network Information Center］ |
| JPS［Japan Photographers' Society］ |
| JR［Japan Railways］ |
| Jr.［junior］ |
| JRA［Japan Racing Association］ |
| JRC［Japan Red Cross Society］ |
| JRCC1［Japan Relief Clothing Center］ |
| JRCC2［Japan Responsible Care Council］ |
| JRDC［Research Development Corporation of Japan］ |
| JSA1［Japan Scientists' Association］ |
| JSA2［Japan Standards Association］ |
| JSB［Japan Satellite Broadcasting Inc.］ |
| JSC1［Japan Science Council］ |
| JSC2［Joint Staff Council］ |
| JSD［Japanese Standard of Dietetic Information］ |
| JSDA1［Japan Securities Dealers Association］ |
| JSDA2［Japan Self-Defense Agency］ |
| JSDF［Japan Self-Defense Forces］ |
| JSF［Japan Science Foundation］ |
| JSNP［Japan Satellite News Pool］ |
| JSP［Japan Socialist Party］ |
| JSPS［Japan Society for the Promotion of Science］ |
| JST［Japan Standard Time］ |
| JSTARS［joint surveillance target attack radar system］ |
| JT1［Japan Tobacco］ |
| JT2［Johnston Island］ |
| JT-60［JAERI Tokamak-60］ |
| JTA1［Japan Tennis Association］ |
| JTA2［Japan Tourism Association］ |
| JTB［Japan Travel Bureau］ |
| JTIDS［joint tactical information distribution system］ |
| JTTA［Japan Table Tennis Association］ |
| JTU［Japan Teachers' Union］ |
| JTUC［Japan Trade Union Confederation］ |
| JUSB［Japanese University Sports Board］ |
| JV［joint venture］ |
| JVA［Japan Volleyball Association］ |
| JVC［Japan International Volunteer Center］ |
| JWA1［Japan Weather Association］ |
| JWA2［Japan Whaling Association］ |
| JYA［Japan Yachting Association］ |