Based on the analysis of the MODIS data spectrum characteristics, and synthesis application of 3S technology, a work flow and quantified indexes to process the remote sensing data for monitoring the wheat straw burning in the field after harvest are suggested. These methods are successfully used to monitor this circumstance in Guanzhong Area in 2004.This work not only has significance for government to quickly and fully find out the situation of wheat straw burning, but also can improve the ability and efficiency of supervising this sort of happening.