Abstract: In order to integrate the stumpage volume caculating method with that of the felled tree and overcome the unjointment of the stumpage volume table and merchantable volume table, the materials of the seedling Chinese fir in ZheJinag Province was selected in this essay. The mathematical methods to describe the stem profiles was studied, the new concept of the variable form factor was advocated and the new variable taper models derivated. After the comparing of different taper models, the optimum variable taper models was selected to construct a Two-way variable merchantable volume table. If the data of D. b. h. and H for a single tree was inputed into computer, the precise total volume and different merchantable volume could be obtained consistently. This provide the index basis about forest resource’ s quantity and quality for the purpose of scientific forest management reasonably exploitation and utilization and realizing of limited cutting plan.