Abstract： A method for determining the in vitro release of nifedipine(1)sustained-release tablets(Ⅰ)was established by using the reciprocating cylinder dissolution testing device,and parameters such as the volume of release medium,screen mesh size,immersion time,drip time,surfactant,defoamer,and reciprocating rate were investigated.The release curves of three batches of generic preparation samples with different release rates in vivo were determined under the optimized conditions of 900 mL medium without adding surfactants;the mesh size of upper screen and lower screen were 590 μm and 38 μm;5 seconds immersion time;60 seconds drip time;reciprocating rate 5 dip/min using multi-row mode of large dissolving cup method,and were compared with the release curves of reference preparations.The results showed that the determination method established in this study could distinguish generic preparation samples with different release rates,but the in vitro-in vivo correlation of the method was unsatisfactory.