A data storage apparatus and a method for preventing data error using the same are provided. The data storage apparatus includes a memory and a memory controller. The memory includes a plurality of blocks. The memory controller is coupled to the memory and configured to perform the following operations: recording a read count of a target block of the memory; performing an error bit check on a free storage space of the target block when the read count of the target block meets a condition; and programming a dummy data to the free storage space of the target block in response to the determination that the check result is negative.