The ESRI’s OCX named MapObjects Java Standard Edition (MOJava) has been in troduced in the paper. The main function and characteristic of MapObjectsalso have been introduced. A case in point of application GIS for ancient and precious trees in the scenic park of Dr. Sun Yat-sen’s Mausoleum, Some GIS functions based on MOJava have been analyzed. The conclusion shows thai Map()bjects Java Standard Edition is a rich collection of client and server components for Java developers. ComGIS integrates GIS with special model so closely that it can accomplish not only some functions of GIS but also many functions of,the special application,and it can be platform crossing and extendable.