The scope， members， working groups and annual meeting arrangement of CIGRE SC-B5 are introduced first in this paper. On CIGRE Session 2008， two preferential subjects for B5 are:Impact of process-bus（IEC 61850-9-2） on protection and substation automation systems; Life cycle management of protection and control systems. Encouraged by successful application of IEC 61850 on station bus， people now research digitalized interface of instrument transformer， circuit breaker， isolator and earthing switch， and allocation of merging unit. The most recent development in these aspects is provided. The application of digital equipments and system brings about two consequences:on one hand， with the help of powerful self diagnose test ability of equipment， it is possible to prolong time interval of periodical test， reduce periodical test items， or even cancel periodical test totally; on the other hand， not so observable digital signal & more frequent upgrade of equipment also bring about challenges to maintenance.