Abstract: The uncertainty and the risk of R&D activity result in the low effect of the R&D cost management; a project lifecycle theory is introduced into the R&D cost management. By analyzing the cost cause and its risk of R&D project lifecycle, the cost management mode based on the project lifecycle is explored. The mode divided the R&D cost management into four stages, these are strategic cost management of initiated stage, risk cost management of advance developing stage, quality cost management of design developing stage, and goal cost management of industry tests stage. It makes the key of R&D cost management in every stage more definitively, and the uncontrollability of overall R&D is transtered into key controllable for each stage, and it is in favor of efficiency advance for the R&D cost management.