Abstract: Construction projects commonly have 4 stages including design, development, construction and building and putting into production. This process is called " project development cycle". Feasibility study and project assessment hold the balance in project development cycle. This paper introduces the definitions, basic contents, job program, targets and functions of feasibility study and project assessment. It is hoped to provide some references for preceding management, normalization of corresponding management program and ensuring scientific decision -making of the construction projects of SINOPEC.