From the point of view of real application of multifingered hand, the problem of estimating the gravity of a grasped object and the wrench exerted on the object by the external environment, using multifingered hand equipped with force/torque sensors, is addressed. At first the problem is modeled mathematically by the concept of wrench, then gravitational effect of fingertips is taken into accounted to eliminate the biasing effect in real implementation. On experimental system HKUST HAND, some experiments are carried out to implement and verify the proposed approach. This is an introduction to real application of multifingered hand, such as assembly of parts.