In order to improve the operating reliability of the 35 kV electric transforming and distributing system, Zhejiang Gala Chemical Corp. combined the substation operation situation and carried on automation transformation. Various types of relay protection composed of separate components were transformed into the micro-computer protecting device. The improved 35 kV system architecture, system automatic transforming, the protecting functions adjusting and background monitoring system design were introduced. The operation indicated that the transformation enhanced the accuracy and reliability of the system protection, and not only improved power supply reliability but also saved manpower and reduced running cost.