Abstract: The photoperiodical response of specie3 in Oryza and some populations ofChinese common wild rice (Oryza ruAsogco Griff. in China) were studied comparativelyin this paper. The results showed that experimental materials can early heading after short-day treatment. There were some relation between their senstive degree to the induce of short-day and chromosome set. The species of AAchromosome set had obviously different response to photoperiod. The different degrees of response to short-day among Dongxiang,Chalin,Jiangyong and Renhua wild rices (O, rufipogon Griff. in China) have relative to do with their different geographical distribution,namely those which were at higher altitude had lower degree of response to short-day. On the other hand,we also did some studies on the difference of photoperiodical reaction in population and leaf stage effects.