The results are presented of a study to tropospheric NO 2 over China, based on measurements from the satellite instruments GOME and SCIAMACHY. A data set of 10 year tropospheric NO 2 has been processed from GOME and SCIAMACHY observations using a combined retrieval/assimilation approach. This approach allows the retrieval of global, accurate tropospheric concentrations and detailed error estimates. The resulting dataset has been analysed with statistical methods to derive trends in NO 2 and the seasonal variability on a grid of 1×1 degree for all regions of China. The variance and the autocorrelation of the noise are used to calculate the significance of the trend. The results show a large growth of tropospheric NO 2 over eastern China, especially above the industrial areas with a fast economical growth. The seasonal pattern of the NO 2 concentration shows a clear difference between East and West China. This spatial difference correlates with the dominating source of emissions.