An operating method of a nonvolatile memory device includes receiving a read command from a memory controller; determining a read mode based on the received read command, controlling a precharge time and an offset of a precharge control signal according to the determination result, and precharging a sensing bit line among bit lines to a precharge voltage based on the controlled precharge control signal. The sensing bit line is a bit line being precharged according to the determined read mode among the bit lines.