We propose a new quantum key distribution scheme based on random phase coding. In this scheme, the sender and the receiver can share the secret information without basis reconciliation,and besides, this scheme is more efficient. As the phase of the qubit is coded randomly, this protocol is robust even when the source is not a prefect single photon. We show theoretically that it has higher security against the attacks, such as the photon-number-splitting, the impersonation attack, and the Trojan attack, etc., than the previous QKD scheme.