Abstract: The increasing of the load in the distribution network will advance the expansion time of the power supply equipment, and improve the value of expansion investment. According to the structure of weakly meshed distribution network, the conception and calculation method of current distribution coefficient matrix, which can reflect the distribution of the power flow, are proposed. The sensitivity coefficient matrix is built by combining the sensitivity of node power injection-branch current and current distribution coefficient matrix. And the locational marginal capacity cost (LMCC), which represents the capacity cost of each node, can be calculated. The sensitivity coefficient matrix depending on the Jacobi matrix is improved to calculate the LMCC, and the IEEE33 distribution system is used as test example to verify the feasibility of the method proposed in this paper.