Abstract: In this paper, an improved low-profile inverted-F antenna is presented. Compared with conventional inverted-F antenna, this antenna can produce wider frequency bandwidth by adding parasitic elements on two sides and in the bettom simultaneously. The influence of primary structure parameters on the input impendence and resonance frequency is analyzed. Based on the study above, an improved low-profile inverted-F antenna with three parasitic elements at 1.2GHz is designed, simulated and analyzed. It can be concluded from the good result that the frequency bandwidth can reach 33% for a VSWR = 2, which is more than four times as wide as that of a conventional inverted-F antenna. This antenna has great potential in practical application.