This paper proposes Proxy Certificate Trust List (PCTL) to efficiently record trusted delegation trace for grid computing. Our solution based on PCTL provides functions as follows: (1) On-demand inquiry service for real time delegation information of grid computing underway; (2) Lightweight mutual authentication that is beneficial for proxy nodes with short life span or limited computation power as wireless devices in mobile computing; (3) A kind of revocation mechanism for proxy certificates to improve the security and availability of grid computing.