The IEEE 802.16e standard known as Mobile WiMAX has recently been introduced. It is considered as one of the most promising wireless access technologies supporting high data throughput with low cost of deployment. Mobile WiMAX makes use of Orthogonal Frequency-Division Multiple Access (OFDMA) digital modulation scheme as the transmission method. With the constraint requires that all requests have to be mapped as a rectangle, it is shown that finding an optimum mapping solution is an NP-complete problem. Many burst mapping algorithms have been proposed, but none considered the case with prioritized requests. This paper presents an efficient packing algorithm for two-level requests with two targets: (1) map high (MUST part) priority data as much as possible; and (2) achieve high efficiency, reduces the number of unused slots, and minimizes the mapping information overhead. Simulation results show that the proposed algorithm achieves high efficiency.