A data writing method for writing data into a physical erasing unit and a memory controller and a memory storage apparatus using the data writing method are provided. The method includes dividing the data into a plurality of information frames in a unit of one physical programming unit. The method also includes writing the information frames in sequence into at least one physical programming unit constituted by memory cells disposed on at least one first word line and programming the storage state of memory cells disposed on at least one second word line following the first word line to an auxiliary pattern. Accordingly, the method effectively prevents data stored in the physical erasing unit, which is not full of data, from being lost due to a high temperature.