In view of the shortcoming of the traditional definition of electrical distance， a new way to calculate the electrical distance is proposed in this paper called spatial electrical distance. All the buses in the system are mapped into the multi-dimensional space as different spatial points according to the buses’ variety relation of their reactive power and voltage， and the distance between the spatial points is defined as the spatial electrical distance. Thus the network partitioning for reactive power/voltage control is transformed into the spatial clustering problem. The immune-central point clustering algorithm of network partitioning for reactive power/voltage control is proposed taking into account the characteristic of partitioning for reactive power/voltage control， and then it is used in IEEE 118-bus system. The partitioning result is analyzed in detail and compared with the other algorithm to show the accuracy and feasibility of the proposed algorithm.