Wireless sensor networking is an emerging technology that has a wide range of potential applications including monitoring, medical systems, real-time, robotic exploration and etc. Energy is a critical resource in battery-powered sensor networks. Medium access control has an important role in minimizing energy consumption while it is responsible for successful data transferring in the network. Periodic data collection is the most comprehensive way of data gathering mechanism in wireless sensor network in which nodes report their samples in specific time intervals. It is possible to have some nodes with different update intervals in the network and therefore, finding a solution to accommodate nodes with different sampling intervals while maintaining the energy efficiency is the primary concern of this thesis. In this work, we propose a schedule-based MAC protocol that supports periodic traffic with different sampling rates in an energy efficient manner while maintaining minimum packet loss and end-to-end delay. The schedule-based MAC design is used for eliminating the idle listening problem which leads to smaller energy consumption. We introduce a traffic adaptive technique that arranges the time schedule of each node with respect to its sampling rate. Route partitioning technique is the next step of our design to provide a collision free data transfer. By this mechanism, each route will be activated in a specific time regarding to the sampling interval of nodes that it involves. Using the enhanced time scheduling and route partitioning techniques with respect to nodes' sampling rate provides the basic design of our traffic adaptive algorithm. In order to represent traffic adaptive capability of the proposed protocol, some nodes are considered to generate data packets with higher data generation rates than other sensor motes in the network. The most relevant existing MAC protocol which support only one generation rate is then compared with our modified version. We then analyzed the estimated energy consumption and defined the maximum number of high sampling rate nodes that can be supported by the proposed protocol. The simulation results show that our adaptive protocol provides a minimum packet delay and the least packet loss rate compared to existing MAC protocol. The energy dissipation of the proposed protocol is much less than the existing MAC protocol when its duty cycle has been adjusted with respect to high traffic node's sampling rate. The proposed traffic adaptive MAC design can achieve around 35% improvement on energy efficiency while maintaining minimum end-to-end delay and packet loss rate.