The data from 18 sites of TCCON are used for the validation of GOSAT XCO2 products from 2009 to 2017, which show a consistency between satellite data and groundbased measurements. Biases between the satellite data and groundbased measurements in East Asia, North America, Europe and Oceania are 2.23±2.69, 2.19±2.19, 2.01±2.49， 1.59±1.79 ppm, respectively, and the correlation coefficient is not less than 0.75. The accuracy of satellite products is higher in the range of 30°S-60°N, but slightly lower in high latitudes. In addition, authors also use GOSAT L2 XCO2 products to analyze the change of global atmospheric CO2 in longterm sequence. The results show that the concentration of global atmospheric CO2 shows a continuous upward trend from 2009 to 2017, and the global average annual growth rate is 2.22 ppm·a-1. There are some fastgrowing countries and regions, including China, the United States, India, and Africa. Influenced by natural emissions of El Ni〖AKn~D〗o, the concentration of atmospheric CO2 grew the fastest in 2016, with the growth rate being more than 3 ppm·a-1.