Load flow study on distribution system sometime is not effective for radial power system, which have many distributed loads. This un-effectiveness caused by the bus model for distribution transformer is a load bus in a load flow study. A mathematical model for representing distributed load as lumped load is needed for reducing distributed loads. This research is subjected to make a distribution load model as lumped load by using mass center formula (TPM model) based on lumped load model,  Cheng and Shirmohammadi. This models are validated using MATPOWER ver. 3.0.0 load flow to compare model outputs and real condition outputs of distributed loads. Output variables of research is sending power (Ps), sending reactive power (Qs), voltage magnitude (Vr) and angle (r). Validation of these models use standard distribution system (SPLN) and implemented on Gunung Sari Feeder, Lombok. Results of research are TPM model has better than CS95 model. TPM model has error percentage : Ps 0.8780%, Qs 0.6860%, Vr 0.2782% and r 0.637375%. CS95 Model has error percentage: Ps 1.6222%, Qs 1.1843%, Vr 0.8080% and r 7,0762% on standar distribution system (SPLN). Implemented these models on Gunung Sari Feeder, TPM model also has better than CS95 Model. TPM model has error percentage: Ps 0.5155%, Qs 1.0417%, Vr 0% and r 2.0875%, CS95 model has error percentage: Ps 0.5155%, Qs 1.0417%, Vr 0.3566% and r 25.5249%.