SAR interferometry(InSAR) technology uses the phase information of single look complex(SLC) SAR data to get three-dimensional information of the earth surface. This technology has been in the front line of radar field since last decade. In recent years

this technology has been widely used in many remote sensing fields. To research the effect of wavelength to InSAR DEM

in the test site of Jiagedaqi district

Heilongjiang province

DEMs are generated from SIR-C/X-SAR C-band and L-band single look complex(SLC) data. There are some differences between them. Then the analysis are taken with interferometric coherence

phase unwrapping etc. So the relationships between accurate of DEMgenerated from InSAR and coherence

wavelength are illustrated

which also demonstrates the feasibility and affecting factor of DEM generated from InSAR. At last

1∶50 000 topographic map is used to evaluate the accurate of DEM. The effects of ground control points’(GCP) accurate are analyzed to InSAR DEM.