J2ME是Java 2平台的一个版本，使用在各种各样的消费电子产品和嵌入式设备上。Java Card技术规范得Java应用能运行在智能卡和更小的嵌入式设备上。本文介绍J2ME和Java Card的硬件平台和软件体系结构，以及如何进行J2ME和Java Card应用程序开发。Java在移动通信领域的应用已经引起广泛的关注，本文对此进行了详细的描述。-J2ME Java 2 Platform, a version of used in a wide range of consumer electronic products and embedded devices. Java Card specifications in Java applications can run on smart cards and small embedded devices. This paper introduces J2ME and Java Card hardware platforms and software architecture, and how J2ME and Java Card application development. Java in the area of mobile communications applications has attracted widespread attention, the paper carried a detailed descr iption.