A data writing method for a rewritable non-volatile memory module is provided. The method includes recording a plurality of characteristic parameters corresponding to a plurality of data to be programmed; arranging the data according to the characteristic parameters and identifying frequently-read data among the plurality of data according to the characteristic parameters, and programming the frequently-read data into a first physical programming unit of a rewritable non-volatile memory module, wherein a time for reading data from the first physical programming unit is less than a time for reading data from a second physical programming unit of the rewritable non-volatile memory module. Accordingly, the reading performance for the data can be effectively improved.