When a patch antenna is undergoing strain, causing the antenna to deform, its resonance frequency shifts accordingly. Based on this principle, a strain sensor with patched antenna can be used for monitoring strain in structural members. This paper adopts 2.4GHz quarter-wave rectangular patched antennas as strain-sensing units. Firstly, the dimension parameters of patched antennas are determined via HFSSTM, and the resonance frequency shifting of the antennas is simulated when antennas are undergoing the tension strain in length and width direction respectively. Then, the antennas are glued on the surface of aluminum plates along the longitudinal and transverse direction respectively. The resonance frequency of antennas under different stressing level is identified via network analyzer. Both the simulation and test results show there is a good linear relationship between resonance frequency variation and the strain in length direction, while the width variation of the rectangular patched antenna has limited influence on the variation of resonance frequency.