An method for creating a index of the data blocks is applicable in data de-duplication procedure, includes loading an index file, the index file includes a plurality of location blocks, each location block includes a plurality of storage fields, and each storage field records a primary Hash value corresponding to the data block; performing a first Hash procedure on a primary Hash value of the data block and calculating a block number; performing a second Hash procedure on the primary Hash value in the same data block and calculating a field number; loading a location conflict list; comparing the field number with the field number in the location conflict list to search whether the same field number is stored in the location conflict list; writing the primary Hash value into the corresponding block number and the field number if the field number does not exist in the location conflict list.