There are many researches on requirements dependencies. However, most of them limit their views to the requirements phase of software development, few focus on the roles of requirements dependencies in the solution space of software. This paper presents a feature-oriented approach to modeling requirements dependencies. A feature is a set of tight-related requirements from user/customer-views. The featureorientation provides a modular way to organize requirements and a proper granularity to analyze requirements dependencies. In this approach, we care about not only static feature dependencies (i.e. refinements and constraints), but also feature dependencies at the specification level (namely influences) and, furthermore, dynamic feature dependencies (namely interactions). Moreover, we also explore the underlying connections between these four kinds of feature dependency. By this way, this approach gives a more complete view of how requirements dependencies influence the whole process of software development.