Economic, environmental and social impacts have increased popularity of car sharing program. More firms consider entering this market to satisfy rising demands from public. In general, a car sharing company faces two very practical problems: 1). Station Size/Capacity;  2). Strategies for imbalance of vehicles distribution for each station. Although literature presents that such questions have been studied in the past, almost all of them use optimization models to address these questions; and the problem of those optimization models is these optimization models are specifically question-oriented, therefore it is difficult to be implemented in practice and cannot be easily generalized in common situations. In this study, we develop a novel model to address these questions. Our models require few inputs and offer quick analytic results. An application of the models on Zipcar illustrates how our models work and shows that our models perform well, achieving expectations.