Abstract: By using the precise point positioning with GNSS single station receiver, a method of estimating atmospheric structure constant C_n² is introduced based on the time correlation of tropospheric zenith delay and atmospheric refractive index which uses classical Kolmogorov-Obukhov "2/3" turbulence theory and random field theory. By computing C_n² in Beijing, Shanghai, Kunming and Urumchi, the D-InSAR deformation errors are analyzed at different areas, and the results show that if the baseline is larger than 1km and C_n² is larger than 10^-14m^-2/3, the deformation errors is at centimeter-scale. It is essential to obtain the C_n² exactly during the imaging time of SAR, and the deformation error of D-InSAR can be decreased significantly.