Herein, This paper analyzed the effect of applying the volt-var curve on the smart inverter to solve the over-voltage problem caused by increasing the distributed generation. To analyze the voltage characteristics due to the increase in distributed power connection, the voltage characteristics at the end of the test model were analyzed while increasing the distributed power capacity. The potential hosting capacity was analyzed by calculating the voltage margin up to the upper limit according to volt-var curve types with different reactive power contributions and dead-band. In addition, mounting the volt-var curve to many distributed generation connected to the distribution system faced a practical limitation. Considering this limitation, the voltage characteristics and hosting capacity margins for the penetration level of the volt-var curve were analyzed. In this paper, the effect of the volt-var curve was analyzed using OpenDSS, a quasi-static time-series simulation, considering the characteristics of the distribution system test model in the worst case.