Abstract: Improving the performance of differential protection for power transformers has been drawing lots of concerns of researchers and engineers in the field of power engineering.This paper proposes a novel differential protection scheme based on morphological skeleton（MS）for power transformers.The proposed scheme consists of two parts which are respectively implemented in two adaptive data windows to calculate the MS of differential current waveform.It employs different features of the skeleton points to distinguish internal faults from disturbances（magnetizing inrush current and external fault）.The first part aims to identify internal faults and disturbances as soon as possible under most conditions,while the second part acts as a backup of the first part under some extreme conditions so as to ensure the accuracy.The PSCAD/EMTDC simulation and laboratory experiment demonstrate that the proposed scheme is fast and reliable.