Abstract: In order to affirm the pregnant time to so as the drug to be delivered,we should know the pregnant day 1 of rats,we cohabited the rats in the ovulatory time by examination of the vaginal smear and the second day was regarded as the pregnant day 1.There is no difference from the traditional way,however this method is easy and simple to grasp.

Key words: Cohabitating in ovulatory period, Pregnant day

摘要： 孕期给药需提供准确的致孕时间 ,通过采用大鼠阴道涂片特征来确定大鼠合笼时机 ,排卵期合笼的第 2d定为怀孕第 1d ,与传统的方法比较 ,这种方法简单可行 ,可充分利用资源

关键词: 排卵期合笼法, 致孕时间