Microwave ablation is the most recent development in the field of tumor ablation. Because of its promising advantages to effectively treat deep-seated, nonresectable hepatic tumors, it has driven the researchers to develop new innovative antennas. In this paper choke antenna is compared with extended tip choke antenna, for microwave interstitial ablation therapy. Although clinical trials are the ultimate test for evaluating the performance of antennas, but simulated models play a crucial role while the designing the antennas for MWA -serving as a quick, convenient and inexpensive evaluation to isolate and optimize promising devices for prototyping. Two dimensional Finite Element Method (FEM) is used to simulate, measure and compare the results of both the antennas. While noting the similarities and differences between the heating patterns near the tip of the antenna, it was found that extended tip coaxial antenna provides good impedance matching, less prone to backward heating and produce more spherical heat lesion with respect to coaxial choke antenna.