A data transmission method using automatic repeat request (ARQ) in a radio interface protocol system consisting of a plurality of layers is provided. The method includes delivering, from an upper layer to a lower layer, a data block stored in an ARQ buffer, the ARQ buffer storing a plurality of data blocks to be transmitted in response the lower layer, the data block; delivering, from the upper layer to the lower layer, a new data block stored in the ARQ buffer if a delivery success message is received from the lower layer, the delivery success message indicating successful transmission of the data block; and shifting a window of the ARQ buffer. The present invention can effectively use radio resources since an ARQ procedure does not require a polling process and a process of receiving a status PDU, and is suitable for high rate data transmission.