Heat shock protein, denoted by HSP throughout this paper for the simplicity, is one of the families of proteins which plays an important role to keep the normal activity of a cell. Actually, when a cell is given a stress by heat, metal ion, alcohol and so on, HSP is synthesized a lot to keep the life of a cell from such stress. In this paper, we pay attention to the biochemical reaction of HSP synthesis (especially, in a tumor cell) and research the key-pathway in the reaction. This research is the base to control the behaviour of tumor by using the heat shock stress.