| 序号 | 英文 | 音标 | 词性 | 中文 |
| | IRSC | | | =International Radium Standard Commission 国际镭标准委员会 |
| | IRU | | | =International Radio Union 国际无线电协会 |
| | IS | | | =Indian Standard 印度标准 |
| | ISA | | abbr. | [计] Industry Standard Architecture 工业标准结构 |
| | ISA relation | | | “是一成员”的关系(ISA即is a ) |
| | ISAM | | | [计] 索引顺序存取法 |
| | ISB | | | =Independent Sideband 独立边(频)带 |
| | ISBL | | | [计] 信息系统基础语言 |
| | ISBN | | abbr. | 国际标准图书编号(int.ernational Standard Book Number) |
| | ISC | | | =Industrial Security Committee 工业安全委员会 |
| | ISCAN | | | =Inertialess Steerable Communication Antenna无惯性可控通信天线 |
| | ISCOS | | | =Intergovernmental Standing Committee on Shipping政府间常设航运委员会 |
| | ISD | | | International Subscriber Dialing,国际订户拨号 |
| | ISDN | | n.；abbr. | n. 综合业务服务网；abbr. Integrated Services Digital Network, 综合服务数字网 |
| | ISDX | | | [计] 综合服务数字网 |
| | ISF | | | 信息系统加工线,信息系统工厂 |
| | ISFA | | | =International Scientific Film Association 国际科学电影协会 |
| | ISI | | | =Indian Standards Institution印度标准学会 |
| | ISIC | | | =International Standard Industrial Classification国际标准工业分类法 |
| | ISIS | | | =Institute of Scrap Iron and Steel 废钢铁协会[美] |
| | ISLN | | | [计]综合业务局部网 |
| | ISM | | | =Industrial Security Manual 工业安全手册 |
| | ISMEC | | | 机械工程情报服务 |
| | ISN | | | internal statement number [计] 内码 |
| | ISO | `aIsEu | abbr. | 国际标准化组织(International Organization for Standardization) |
| | ISO container | | | 国际标准化组织集装箱 |
| | ISOC | | | [计]Internet 协会 |
| | ISP | | | Internet服务提供者 |
| | ISP internet | | | [计] 服务提供商 |
| | ISR | | | [计]中断服务程序 |
| | ISRC | | | =International Standard Recording Code 国际标准记录码(ISO) |
| | ISRS | | | =Information Storage and Retrieval Systems 情报存贮与检索系统 |
| | ISRSA | | | =International Synthetic Rubber Safety Association 国际合成橡胶安全协会 |
| | ISRU | | | =International Scientific Radio Union 国际无线电科学联合会 |
| | ISS | | | =Industry Standard Specification 工业标准规格 |
| | ISSMFE | | | =International Society for Soil Mechanics and Foundation Engineering 国际土壤力学与基础工程学会 |
| | ISSN | | abbr. | 国际标准期刊编号 |
| | ISSP | | | 政策计划情报系统 |
| | IST | | abbr. | insulin shock therapy 胰岛素休克疗法 |
| | ISU | | abbr. | [军] Itegrated Sight-Unit, 整体式瞄准镜装置 |
| | ISV | | | 独立软件开发商 |
| | IT | | | =Information Theory 信息论 |
| | ITA | | | =Independent Television Authority 独立电视管理局[英] |
| | ITC | | | =Infantry Training Centre 步兵训练中心 |
| | ITE | | | =Institute of Traffic Engineers 交通工程师学会[美] |
| | ITG | | | =Iterative Test Generator 迭代测试程序, 重复测试生成程序 |
| | ITN | | abbr. | Independent Television News(英国)独立电视新闻公司 |
| | ITO | | | =International Trade Organization 国际贸易组织 |
| | ITOS | | | 改进型电视与红外观测卫星式作战卫星 |
| | ITPR | | | =Infrared Temperature Profile Radiometer 红外温度廓线辐射计 |
| | ITR | | abbr. | Internet Talk Radio 因特网（国际互联网）广播台 |
| | ITT | | abbr. | International Telephone and Telegraph Corp. 美国国际电话电信公司(=IT&T) |
| | ITTF | | abbr. | International Table Tennis Federation 国际乒乓球联合会 |
| | ITU | | abbr. | International Telecommunications Union,国际电信同盟 |
| | ITV | | abbr. | （英国）独立电视台 (Independent Television) |
| | IU | | | =Interference Unit 干扰器 |
| | IUB | | | =International Union of Biochemistry 国际生物化学联合会(ICSU) |
| | IUBS | | | =International Union of Biological Sciences 国际生物科学联合会(ICSU) |
| | IUCN | | | =International Union for the Conservation of Nature and Natural Resources 国际自然与自然资源保护联合会[瑞士] |
| | IUCR | | | =International Union of Crystallography 国际结晶学联合会(ICSU) |
| | IUD | | | =Institute for Urban Development 都市发展学会[美] |
| | IUFRO | | | =International Union of Forest Research Organizations 国际林业研究机构联合会 |
| | IUGG | | | =International Union of Geodesy and Geophysics 国际大地测量地球物理学联合会 |
| | IULA | | abbr. | 世界地方自治联盟 |
| | IULIA | | | =International Union of Life Insurance Agents 国际人寿保险商联合会 |
| | IUMI | | | =International Union of Marine Insurance 国际海上保险联合会 |
| | IUP | | | =International Union of Publishers 国际出版商联合会 |
| | IUPAC | | abbr. | International Union of Pure and Applied Chemistry 国际理论和应用化学联合会 |
| | IUPAP | | abbr. | International Union of Pure and Applied Physics 国际理论和应用物理学联合会 |
| | IUPS | | | =International Union of Physiological Sciences 国际生理科学联合会(ICSU) |
| | IUS | | abbr. | International Union of Students 国际学生联合会 |
| | IUTAM | | | =International Union of Theoretical and Applied Mechanics 国际理论与应用力学联合会(ICSU) |
| | IV | | | intravenous 静脉内的 |
| | IVA | | | =Ideal Voltage Amplifier理想电压放大器 |
| | IVBA | | abbr. | International Volleyball Association 国际排球协会 |
| | IVF | | | in-vitro fertilization, 试管受精 |
| | IVM | | | =Induction Vacuum Melting 真空感应熔练 |
| | IW | | | =Induction Welding 感应焊接 |
| | IWS | | | =Inland Waterway Service 内陆航道局[美] |
| | IWSA | | | =International Water Supply Association 国际供水协会 |
| | IWW | | abbr. | Industrial Workers of the World 世界产业工人组织 |
| | IX | | | =Ion Exchange 离子交换 |
| | IYFT | | abbr. | Informtion at Your Finger Tip 信息随手可得(Bill Gates语) |
| | Ia. | | | Iowa 美国衣阿华州州名 |
| | Iago | i:5B:gEu | n. | 埃古(莎士比亚悲剧《奥赛罗》) |
| | Ian | iEn | n. | 伊恩（男子名） |
| | Ianthe | aI`AnWI | n. | 艾安西(f.) |
| | Iasi | `jB:FI | | 雅西[罗马尼亚东北部城市] |
| | Ibada | i5bB:dB: | n. | 伊斯兰教徒在宗教上的责任(如颂经,祷告,朝圣等) |
| | Ibadan | i5bAdEn | | 伊巴丹[尼日利亚西南部城市] |
| | Iberia | ai5biEriE | n. | 古西班牙, 伊比利亚 |
| | Iberian | ai5biEriEn | adj.；n. | adj. 伊比利亚的, 伊比利亚人的；n. 伊比利亚人, 古代伊比利亚人, 伊比利亚岛 |
| | Ibibio | 7ibi5bi:Eu | n. | 伊比比奥族人[语] |
| | Ibiza | | n. | 伊比沙岛(位于地中海西部) |
| | Ibizan | I`vi:WEn | | hound 伊维萨猎犬(体形瘦长、行动敏捷) |
| | Iblis | | n. | (=Eblis)恶魔 |
| | Ibo | 5i:bEu | n. | (尼日利亚东南部的)伊博人[语] |
| | Ibsen | 5ibsen | | 易卜生(①姓氏 ②Henrik, 1828-1906,挪威剧作家及诗人) |
| | Ibsenian | | adj. | 易卜生的 |
| | Ibsenism | `IbsEnIzEm | n. | 易卜生主义 |
| | Ibsenist | | n. | 易卜生的崇拜者, 易卜生派剧作家 |