The bearing capacity is an important check content for concrete and stone piers. Under limit states design method, the material can not bear pulling force in tensile area, and compressive stress presents rectangle distribution. The bearing capacity's calculation is very complicate for round-ended massive piers under this hypothesis. For the convenient design, a reduction factor is introduced similar to the allowance stress state's. It is introduced for the principle and process to solve the reduction factor of compression by using graphic solution. By using multiple regression analysis, it is presented to a group of the reduction factor of compression formulas of round-ended massive piers. The formulas are simple, practical and meet the precision request. They can apply to current design.