Recent years have seen the rapid development of mobile technology, and it is really possible for people to implement collaborative work on mobile instruments. This paper aims to explore the design and implementation of a multi-participant oriented, avatar-based, 3-dimentional CVE running on mobile network and mobile instruments. The paper presents solutions to data transmission restriction, computation limitation, and 3-D display limitation for developing mobile CVE system. Key technologies such as connection keeping, scene data management, and custom protocols are scrutinized. A prototype system of mobile CVE, called Mobile Phone Collaborative Virtual Environment (MOPCVE), is developed with Java ME, Java ME 3D in this study. Mobile CVE is promising to be a new collaborative working mode, whose future possible typical applications may include immersive collaborative mobile phone game, immersive mobile meeting/education, collaborative field investigation and integration with Internet CVE.