The refractive index structure parameter C2n from April to May in 2014 measured by the temperature pulsating instrument and sonic anemometers in Chengdu was statistically analyzed. The results of C2n measured by two methods agree well with each other both in day and at night. Compared with Hefei, the diurnal variation of the C2n is obvious but conversion time is different. Between 10-15 and 10-13 level, C2n frequencies measured by the temperature pulsating instrument and sonic anemometers are 74.05% and 84.40% respectively; the frequencies less than 10-15 are 24.07% and 10.63% respectively; the frequencies greater than 10-13 are 1.89% and 4.97% respectively. The relationship of C2n measured by sonic anemometers and temperature pulsating instrument is y=－8.5694×10－16+0.6520x, the correlation coefficient is 99.24%, and the possible causes of the C2n deviation measured by two methods was analyzed in brief.