Superframe order value and beacon order value on IEEE 802.15.4 protocol determine the number of data packets that can be transmitted in each Superframe and also the length of the inactive period in each Superframe. This study uses Multihop networks. This study uses NS2 simulation to analyze the influence of the Beacon Order value and Superframe Order value to the performance of multihop wireless networks with a tree topology base on IEEE 802.15.4 protocol. The performance of the network which have been evaluated in detail are the average throughput, average delay, delivery ratio and the percentage of the average energy used towards the variation of the Beacon Order value and Superframe Order value. The optimum number of Beacon Order and Superframe Order found from the experiment is 9.