Coupled inductor is one appealing technology to improve transient response and reduce output decoupling significantly in interleaved multi-phase voltage regulators (VRs). One known problem is that there is no mature solution yet to sense the individual phase current accurately in a lossless way for couple inductor based VRs design. This will impact VR some normal function in one phase mode. This paper proposes a new solution to this problem and simulation is conducted to verify effectiveness of the proposal.