The Landsat 5 mission is in jeopardy. Therefore, the United States Geological Survey (USGS) is exploring ways to alleviate a data gap if both Landsat 5 and 7 missions fail prior to the planned launch of Landsat 8 (known as the Landsat Data Continuity Mission) in 2013 [Randy, 2012]. Using the Chinese HJ1-CCD remote sensing data, analyses were performed on the spectral signature of these two different sensors to investigate the substitution of existing sensors for Landsat 5 TM in certain fields of research. In particular, a comparison was made between Landsat 5 TM and the HJ1-CCD in terms of orbital parameters, imaging features and spectral response characteristics, among other characteristics. Thereafter, a comparative analysis was performed on the “at-satellite” reflectance of nine pairs of remote sensing images of different land cover in China, and a mutual quantitative relationship was established. The results indicate that Landsat 5 TM and HJ1-CCD have similar orbital parameters, and the latter has a higher time resolution with advantages in its breadth and the quantity of sensors, although both have the same spatial resolution. Regarding the imaging and spectral response characteristics, although the at-satellite reflectance of HJ1-CCD is different from that of Landsat 5 TM for red, green, blue and near infra-red bands, there is still a broad correlation between HJ1-CCD and Landsat 5 TM, and the coefficient of determination approaches unity. Therefore, a mutual complementation and substitution of the at-satellite reflectance between HJ1-CCD and Landsat 5 TM images is feasible.