Carbon dioxide has an absorption band of solar spectra in SWIR, and temperature is a key factor to the absorption effect. Researches on the CO2 observation sensitivity of temperature are done in this paper. First, the dependences of spectral line parameters on temperature are discussed. Then, according to the accuracy level of atmosphere temperature profile product, we simulate the change of measurement in nadir mode by importing 1 K temperature uncertainty, using line-by-line radiative transfer mode under 6 different atmosphere modes, and calculate the corresponding change of retrieval result. In contrast, simulations of measurement change resulted from 1 ppm and 2 ppm CO2 column density differences are also done. After comparison, we come to a conclusion: 1 K uncertainty of atmosphere temperature profile is an important factor which has significant influence to high precise atmospheric CO2 observation.