A method of storing and accessing an error correcting code in NAND Flash, includes utilizing n pages of a block of the NAND Flash as an extended space of a spare area, n≦1, wherein when writing data, the data is stored in a data area of a sector, and when the error correcting code needs a space which has correcting capability larger than 16 bytes, first 16 bytes of the error correcting code is stored in the 16 bytes spare area, and the remaining of the error correcting code is stored in the extended space of the spare area corresponding to the sector. Therefore, the method develops new storing space for the error correcting code, arranges the error correcting code in sequence of data blocks in sub-space, and loads the error correcting code into system memory for the decoder before reading original data.