In this paper,we applied H-κ stack method of receiver function and time-window sliding method to convert waves of Moho and intra-crustal discontinuity in the teleseismic P wave receiver functions in Xinjiang region during the period 2009~2012. We also analyzed the crustal and upper crustal media Poisson's ratios variations with time before and after the earthquake at the stations near the epicenter of 6 moderate earthquakes in Xinjiang region during the period 2009~2012. The results show that the crustal media Poisson ratio beneath Wusu,Yutian and Dushanzi seismic stations display a relatively obvious and continuous decline process before and after the earthquake,and the decline range is larger than the mean error. In addition,the morphological variation is in "V" type(Wusu station was double "V" type),and the earthquake occurs at the tail of the "V" formation,while the Poisson ratio of upper crustal media does not show a significantly low value anomalies before and after the earthquake. The Poisson ratio of crustal and upper crustal media beneath 4 other seismic stations does not observe significant low-value anomalies before and after the earthquake. Among the 7 stations,no matter whether the Poisson ratio of crustal media before and after the earthquake has observed obvious low value anomalies or not,there are no obvious low value anomalies variations of Poisson's ratio were observed in the upper crustal media. According to the observations in this study,it may indicate that the low value anomalies by the Poisson ratio in the crustal media before and after the three earthquakes may stem from the middle and lower crust,indicating that the crustal seismogenic depths of the 3 moderate earthquakes are located in the middle-lower crust.