Abstract: The granular adulterated properties of water chestnut starch were investigated experimentally by using the modem analytical techniques such as light microscopy and RT- PCR assay. The results showed that eight commercialized samples were pure water chestnut starchs,five in 32 samples were pure tapioca starchs,one was pure corn starch,three were pure potato starchs,three were mixture of water chestnut starch and potato starch,one was mixture of water chestnut starch and tapioca starch,one was mixture of water chestnut starch and corn starch,five were mixture of tapioca starch and corn starch,three were mixture of tapioca starch and potato starch,two were mixture of tapioca starch,corn starch and potato starch.The results using microscopy was consistent with that of RT- PCR assay.Two kinds of detection methods could be used as product quality supervision of domestic starch market.