In this study, the knee joint varus and vaglus torque produced by sportswears was caluclated numericaly, and the effect of the torque on a human body was evaluated. The strain of sportswears on a human body was supposed to be represented by the 3-dimensional computer graphics of a human model. The hyperelastic model was applied to reproduces the mechanical characteristic of the fabric materials for the sportswear. Stress distributions of sports compression tights were calculated. The knee joint varus and vaglus torque produced by sports conpression tights during running was calculated by the relationship between the position and force at each node. As a result, the torque varied depending on placement of the materials that made up the tights. The numerical result showed that the possibility of quantitative evaluation of the torque as a support effect to the knee of sports compression tights to the knee joints.