A method and a system for data rebuilding and a memory control circuit unit thereof are provided. The method includes reading a plurality of physical-logical mapping information and a plurality of time information corresponding to the physical-logical mapping information stored in a rewritable non-volatile memory module. The method also includes sorting the plurality of physical-logical mapping information according to the plurality of time information corresponding to the physical-logical mapping information. The method further includes rebuilding a logical-physical mapping table according to the sorted plurality of physical-logical mapping information, and storing the rebuilt logical-physical mapping table into a buffer.