Automatic computation of cross sections in HEP - Status of GRACE system

For the study of reactions in High Energy Physics (HEP) automatic computati on systems have been developed and are widely used nowadays. GRACE is one o f such systems and it has achieved much success in analyzing experimental d ata. Since we deal with the cross section whose value can be given by calcu lating hundreds of Feynman diagrams, we manage the large scale calculation, so that effective symbolic manipulation, the treat of singularity in the n umerical integration are required. The talk will describe the software desi gn of GRACE system and computational techniques in the GRACE.