Coronaviruses are highly transmissible and are pathogenic viruses of the 21st century worldwide. The outbreak of Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2). In general, SARS-CoV-2 viruses are originated in bats or other wild animals and outbreak was originated from the Wuhan city of China at the end of December 2019. At the same time, the transmission of the infection to the human is caused by domestic animals that represent in the habitat the mediator. We especially emphasized the interaction of reservoir, mediator, and human the spread of coronavirus through our proposed model. In this paper, we reviewed current information and established a model of differential equations, which has twelve ODEs with effective parameters to discuss the spread of the infection from the natural reservoir to the mediator, and from them to the human. We show analytical results as boundedness, non-negativity of solution, disease-free equilibrium point, endemic equilibrium point, basic reproduction number, steady state and numerical simulation. We aimed to estimate the numerical result of our model showed that the new incidence of symptomatic and asymptomatic infections, deaths, and isolations under quarantine scenarios. COVID-19 transmission rate among natural reservoir-mediator-human is the main theme of this study.