The concept of the parameter U* has been introduced by the authors to express load transfer in structures. In this paper, an extended definition of U* is introduced for structures under multiple loadings. The new expression of U* with the matrix formulation of internal stiffness can effectively be applied to an efficient calculation of U* distribution. Examples of U* calculation for an actual truck cab structure under multiple loading are demonstrated. Calculation results of U* for cases under multiple loading condition and single loading condition are compared, and the applicability of St. Venant's principle concerning U* distribution is discussed.