Abstract: A novel dual-band microstrip antenna which is fed by 50 Ω microstrip line for wireless local area network (WLAN) applications is analyzed and designed. The antenna with slot loaded on the patch for miniaturization can operate on dual-band. The center operating frequencies of the antenna are 2.44 GHz and 5.20 GHz, and the operating frequency bandwidths are 200 MHz and 1.2 GHz, respectively. The proposed antenna has some advantages, such as low profile, simple structure, easy fabrication, low cost and good omnidirectional radiation patterns. The high-band and low-band of the antenna can be adjusted by simply modifying the radiation patches and gap size parameter.