In this paper, we have formulated the problem of cross layer throughput-maximized dynamic resource management with guaranteed QoS in MIMO OFDM beamforming systems. In order to reduce of the amount of feedback information and computation complexity, OFDM subcarriers are grouped into subchannels based on the fact that adjacent subcarriers experience the same fading. According to characteristics of various traffics in actual networks, four types of traffics are classified. Different class has different QoS requirements and one connection only belongs to one class. Considering MAC QoS requirements, PHY channel side information (CSI) and connection fairness, the scheduling priority factor (SPF) is defined for each connection. Based on the scheduling priority factor, the suboptimal solutions for the formulated problem are obtained. Packets from different connections are queued at the base station. Scheduling and subchannel allocation are operated at jointly. Then, power allocation and bit loading is made for each packet. The performance of our proposed algorithm is also studied by simulation.