Objective To identify the microsatellite instability (MSI) rates in Chinese gastric cancer samples. Methods 29 microsatellite markers were selected to examine 42 paired gastric cancer tissues for MSI on all chromosomes except Y. Results The total frequency of MSI in all 42 gastric cancers was 33.9% with higher rates at loci of D3S1577, D3S1067, D8S279, D9S257, D1S248, D7S520 and D2S147, and the highest rate at D3S1577 and D3S1067(51.35%). MSI varied with different pathological types. The frequencies of...