Most medium voltage (MV) distribution systems are structured in mesh and radially operated to distribute electric power from distribution substations to consumers (distribution transformers). The difficult decision of building a new radial MV topology is which branch should be connected to others and could save cost in constructing for the operator in the first stage of designing and bidding for the new topology. Due to that problem which always occurs during the primary stage of designing proposals for the system, many heuristic algorithms have been implemented to make a convenient to build up distribution systems and analyze costs for the new system. This paper proposes to study from scratch buildup for the new radial topology to the final stage of the project by using and comparing two methods, called Minimum Spanning Tree (MST) Algorithm and Shortest Path (SP) Algorithm to find the shortest routing connection for structuring the topology with the shortest length of conductor and the better voltage profile by using backward forward load flow to modify. In addition, after the new radial topology is built up, the reliability indicator is proposed by identifying the optimal line among the possible connections within the topology. In the final stage, the economy is estimated by considering the cost of conductors, protective devices, labor, and operational expenses over a planning study of 30 years. To validate the proposed method, the standard test distribution system (9-bus test and 25-bus test) and the real distribution system, which is located in Khsach Kandal, Kandal, Cambodia with 47-bus is selected. The result of this paper demonstrates that the radial Medium Voltage (MV) topology is constructed using the Minimum Spanning Tree (MST) algorithm. This approach results in a reduced length of conductor and a faster payback period, despite the fact that the power loss of the SP algorithm is more favorable. However, the capital expenditure (CAPEX) of the SP system remains a significant concern for many investors. In the reliability index tie line connections are selected based on their highest probability of serving as tie lines within the system.