Normally, the original components are lessened or enlarged proportionally to build the geometric similar models when large scale components are tested or studied by means of finite element analysis (FEA). In order to ensure that the same stress-strain states present between the considered model and the original component, the loads corresponding to the original components in proportion should be applied to the geometric similar models. Therefore, it is important to study the load relationships among these geometric similar components with the same stress-strain states. Based on the stress expressions of middle point on the below edge of immobile rectangular cross section beam, the loads'+H26 theoretical relationships are obtained using the similarity theory. The correctness of these relationships is verified by the components under elastic and/or plastic stress-strain states. The conclusions are shown as follows: for the two components with geometric similar coefficient kl, if the concentrated force coefficient is kl, the uniformly distributed line force coefficient is kl, or the uniformly distributed plane force coefficient is 1, then the two components are completely the same in stress-strain state.