Abstract: This paper, on the basis of the practice in building an engineering communication system,reviews several problems in association with reliability and avail ability of communication systems which are made up from domestic electronic products. This review is based on analysing the statistical data gained from tech nical experiments and uses the view point of system engineering.In the aspect of system reliability, the necessity and reasonableness of using grouped redundant technology in system design are explained With the use of this technology,a high reliable system can be formed with domestic electronic products.In the aspect of system availability, various factors which affect the syetem availability,such as system equipments, environmental conditions, maintenances, ect.are discussed. Several measares dealing with these factors are described.Finally, some suggestions on improving domestic electronic products,designing and building system engineering suitble to China's conditions are proposed.