Atmospheric correction is one of the most important pre-processing steps in quantitative remote sensing. To extract quantitative information from the Enhanced Thematic Mapper-Plus (ETM+) imagery accurately, atmospheric correction is a necessary step. Furthermore, multi-temporal images after atmospheric correction can be compared to each other quantitatively. The Second simulation of satellite signal in the solar spectrum (6S) radiative code can process many types of satellite data and provide several standard atmosphere and aerosol models for atmospheric correction. This paper demonstrates atmospheric correction of Landsat ETM+ data using 6S code. Comparing images before and after atmospheric correction, the different of image before and after correction was not obvious using visual interpretation. Therefore, different ground object spectral curves after atmospheric correction are illustrated. They were similar with the standard ground object spectra. The correlation coefficient of ETM+ band 1 to band 4 and NDVI (Normalized Difference Vegetation Index) after atmospheric correction increases. The atmospheric correction removed the atmosphere effect, so the inherent relevant increased. 6S code was an effective tool for atmospheric correction of remote senisng data.