Abstract: A dynamic shadow detection algorithm for aerial images captured by micro unmanned helicopter is presented.To meet the two requirements of the application platform which are high robustness for various environment and high adaptation to moving background,two independent features are extracted based on the analysis of shadow feature set.A modified Co-EM strategy is applied to shadow detection for separate frames.The experimental results show that this algorithm can not only be applied on real micro unmanned helicopter platform,but also provide better detecting results than the regular method which uses color and region features.