Within the framework of the project "Construction of Distributed Global Environmental Database Based on Network", the Laboratory of Remote Sensing Data Analysis of Iwate University developed AVHRR image compositing system GAVICS (Global AVHRR Image Compositing System). This paper describes processing algorithm of radiometric calibration, geometric registration, atmospheric correction, and compositing used in the GAVICS. Using the system, composite AVHRR data sets of Asian region for 1998 and 1999 were developed.