the MAC scheduler is an important and crucial entity of the Long Term Evolution (LTE) and is responsible for efficiently allocating the radio resources among mobile users who have different QoS demands. The scheduler takes different considerations into account such as throughput and fairness when deciding the allocation of the scarce radio resources. LTE is an all IP packet system in which guaranteeing QoS is a real challenge. Therefore the LTE MAC scheduler should consider not only the throughput optimization but also the QoS differentiations in an effective manner. In this paper, we propose a novel LTE downlink MAC scheduling algorithm. The proposed scheduler differentiates between the different QoS classes and their requirements. Two different QoS classifications are considered: Guaranteed Bit Rate (GBR) and non Guaranteed Bit Rate (non-GBR). The proposed scheduler also considers the different users channel conditions and tries to create a balance between the QoS guarantees and the multi-user diversity in a proportional fair manner. The simulation analysis confirms that guaranteeing the different QoS requirements is possible.