The basic operating principle and structural characteristics of traditional Printed IFA (Inverted-F Antenna) are discussed in this paper. And the way of traditional Printed IFA's design has been introduced in detail. An antenna prototype with a small area on a phone board which with Bluetooth tool has been constructed, analyzed and improved with the software HFSS 10.0 of ANSOFT Corporation. The improved Printed IFA has a more small size than the traditional. This improved antenna with low cost, compact structure, easy feeding and convenient design could be applied in Bluetooth system well.