In this paper, a nonlinear mathematical model of COVID-19 was formulated. We proposed a SEIQR model using a system of ordinary differential equations. COVID-19 free equilibrium and endemic equilibrium points of the model are obtained. A basic reproduction number of the model is investigated by the next-generation matrix. The stability analysis of the model equilibrium points was investigated using basic reproduction numbers. The results show that the disease-free equilibrium of the COVID-19 model is stable if the basic reproduction number is less than unity and unstable if the basic reproduction number is greater than unity. Sensitivity analysis was rigorously analyzed. Finally, numerical simulations are presented to illustrate the results.