Recent, as interest in the vehicle communication is high, various techniques have been developed. However, the vehicle communication has a problem due to high-speed mobility of vehicle. Especially V2I (Vehicle-to-Infrastructure) communication has a biggest problem that is deterioration of continuity and reliability caused by frequent hand-off with base station due to high-speed mobility of vehicle. To solve this problem of V2I, it has been developed a variety of techniques related with choosing the appropriate base station and hand off from the past. However, these techniques cannot guarantee a constant connection and reliable communication between the vehicles and the base station. So we proposed method for adjusting data-rate according to the number of periphery AP to solve the problem. In this paper, we describe the proposed method and program algorithm, and compare the BER, FER, throughput performance with the conventional method by simulation result.