Abstract: OBJECTIVE To research the effect of sinker on dissolution of Ropinirole Hydrochloride Extended-release tablet. METHODS according to the dissolution method from FDA, the release of Ropinirole Hydrochloride Extended-release tablet at each time point was compared between without and with sinker. RESULTS adding sinkers could efficiently improve the RSD, but less affect the product whole dissolution rate. CONCLUSION sinkers can control the position of tablet sinking in the vessel. Data are more stable. It is suitable for the product.