A multi-level cell copyback program method in a non-volatile memory device is disclosed. The method includes reading LSB data of a source page, and storing the read LSB data in a second register of a page buffer, transmitting the data stored in the second register to a first register coupled to a data inputting circuit, and storing the transmitted data in the first register, amending the data stored in the first register through the data inputting circuit, transmitting the amended data to the second register, and storing the transmitted data in the second register, and LSB-programming corresponding data to a target page in accordance with the data stored in the second register.