Abstract: The dist ribution and the fi rst epoch measurement of the crustal mov ement o bserv ation network in China are described. The GPS observ atio nal clata of the fiducial network and basic netw ork is processed with di fferent package of GAM IT/GLOBK. The computa tional resultsare obtained with IT RF97 as reference f rame. Results show that the repea tabili ty of baseline N-S compo nent is 2.28+0.87×10^-9×S, the one of E-W component is 3.67+0.82×10^-9×S, and the one of vertical component is 6.84+1.29×10^-9×S, where S is dista nce betw een GPS sta tions withunit of mm. Af ter the integ ral adjustment of the fiducial netwo rk and basic network, it shows that the hori zontal compo nent of coordinate preci sion of stations is 2～3mm, the vertical compo nent is 3～5mm. It can be co ncluded that the first epoch measurements meet the requi rements of design.

Key words: GPS, Baseline, Crustal deformation, Data processing