To analyse the performance of QoS parameters of wireless sensor network by variation in reporting rate using NS-2. The performance metric considered as packet delivery ratio, throughput, delay, routing overheads, avg. energy consumed and avg. residual energy etc. Using NSG tool, 50 nodes are deployed in 1000* 1000 m* m area. The nodes 25, 31, 5 are considered as source node and node 3 as sink node. The AODV protocol is considered as packet transmission and CBR is used for traffic generation in network. To measure the performance of QoS parameters such as packet delivery ratio, throughput, delay, routing overheads, avg. energy consumed and avg. residual energy with 50 nodes were kept static. The graphs plotted by keeping performance metric at Y-axis and reporting rate on X-axis considered as 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 etc. The analysis of performance of QoS parameters shows that for packet delivery ratio the ideal reporting rate is 20 packets per second. As the reporting rate increases delay increases gradually due to congestion. Also the throughput and routing overheads are increased with increasing reporting rate. Minimum energy consumption at 5 packets per second and maximum energy consumes at 50 packets per second. 20 pps is best reporting rate of transmission of packets for proposed network.