A wireless sensor network (WSN) is a wireless network that consists of independent self-directed devices that may be spatially distributed which use physical sensors to monitor physical or environmental conditions. A WSN may have thousands of sensor nodes which may have numerous technical electronic components which include radio, a microcontroller, a battery, sensors and sensor interfaces. In this article the performance analysis of clustering protocols in heterogeneous wireless sensor networks are done for Stable Election Protocol (SEP) and Threshold-Sensitive Stable Election Protocol (TSEP). WSN is an emerging technology that helps in monitoring the physical parameters in various aspects in today’s world in different environments. Reducing the energy consumed and increasing the lifetime of the network become the most significant objectives of the routing protocols due to the energy. constraints of the WSNs. An optimum technique that can be used to prolong the lifetime of any sensor network and decrease the energy consumption is Clustering. The study shows that the two prominent energy efficient clustering protocols for heterogeneous wireless sensor networks is compared with different parameters like throughput, number of Alive nodes and residual energy with the help of software MATLAB and to find the best clustering protocol amongst the two with respect to the lifetime of the network. © Research India Publications.