A level shifter for high-speed level shifting includes a first P-channel transistor, comprising a gate coupled to a drain, and a source coupled to a system voltage; a second P-channel transistor, comprising a gate coupled to the gate of the first P-channel transistor, and a source coupled to the system voltage; a first N-channel transistor, comprising a drain coupled to the drain of the first P-channel transistor, and a source coupled to a ground level; and a second N-channel transistor, comprising a drain coupled to a drain of the second P-channel transistor, and a source coupled to the ground level; wherein the first N-channel transistor and the second N-channel transistor are low-threshold-voltage transistors or native transistors.