A data writing method for writing data from a host system into a plurality of memory dies of a rewritable non-volatile memory storage apparatus is provided. The data writing method includes determining whether the data transmission interface of the host system complies with a first interface standard or a second interface standard. The data writing method also includes using a general mode to write the data into the memory dies when the data transmission interface of the host system complies with the first interface standard and using a power saving mode to write the data into the memory dies when the data transmission interface of the host system complies with the second interface standard. Accordingly, the data writing method can effectively prevent the stability of the rewritable non-volatile memory storage apparatus from reducing due to insufficient power supplied by the data transmission interface.