The standalone single-phase H-bridge inverter usually works in voltage-mode control, converting DC power to AC local loads. Due to the diversity of loads, the inverter may have rich dynamic behaviors. Oscillation instability occurs when the inductive loads (e.g., electric machine and air conditioner) are connected to AC output of the inverter. Firstly, a mathematical model is established for the single-phase inverter system, and the linearization is processed by taking into account the characteristics of proportional-resonant (PR) controller. Then the inverter output impedance can be derived. Secondly, according to the Nyquist criterion, the impedance ratio curves are plotted to determine the forbidden region of operation. The forbidden region is studied in an analytical way by varying the inductive load, control factor and filter capacitor. The results show that single-phase inverters with inductive loads can achieve stability by the reduction of proportional coefficient and filter inductance, or increase of filter capacitance and series resistor filter inductance in practical parameter ranges. This work is supported by Youth Science Fund of National Natural Science Foundation of China (No. 51507118), Hubei Science and Technology Support Program (No. 2015BAA109), and Fundamental Research Funds for the Central Universities (No. 410500078).