Objective:To study the method of accelerated release of octreotide acetate microspheres for injection in vitro,and to establish the correlation between in vivo and in vitro. Methods:The rotating-bottle method and the flow-through cell method were established. Rotational speed,flow velocity,temperature,p H value,sample pool of species,the arrangement of membrane,glass bead and influence factors such as the way for the accelerated release in vitro was investigated,and the flow-through cell methodwith the temperature of 37 °C,tablet cell (22.6 mm),speed 16 m L·min∼(-1) and p H 10.0 buffer,and the rotating-bottle method with the temperature of 37 °C,of 6 r·min∼(-1) and p H 10.0 bufferwas compared. The concentration of octreotide in rat plasma was determined by LC-MS method. Results:The release rates of octreotide acetate microspheres for injection with the flow-through cell method were faster than that with the rotating-bottle method. The results of the two methods showed the same trend,indicating that the release of brand A was faster than that of brand B. The correlation coefficient r form the linear regression anal. of the correlation between in vitro accelerated release and in vivo release by the flow-through cell method was 0.998 2 and 0.960 9 for brand A and brand B,resp. Conclusion:The accelerated in vitro release measured with the flow-through cell method is faster than that by the rotating-bottle method,and has a good correlation with the in vivo release(r>0.9). The method could be a reference for the evaluation of the in vivo and in vitro release of octreotide acetate microspheres for injection.