A method for programming a non-volatile memory structure with four-page data, wherein the method comprises, in a first stage, selecting four programmable states of a segment of MLC NAND-type memory cells, programming at least a first of the four programmable states with two pages of a four-page data at a first step voltage level, between programming at least two neighboring programmable states of the four programmable states, increasing the first step voltage level to a second step voltage level for a single program pulse and according to a pre-determined magnitude, and programming a latter of the at least two neighboring programmable states at the first step voltage level.