An electronic device for initializing a data storage is provided. The data storage has been accessed. The data storage includes a plurality blocks, which comprise some bad blocks. Each block comprising a block marking area for writing a block identifier. The block identifier is for marking whether the block is a bad block or a good block. After the data storage is accessed, a bad-block table for recording the block identifier of each block is stored at a predetermined location of the data storage. When initializing the data storage, the electronic device accesses the bad-block table from the predetermined location of the data storage, erases data stored on the data storage, obtains the block identifier of each block from the bad-block table; and writes the block identifier to the block marking area of each block.