A data storing method, a memory control circuit unit and a memory storage device are provided. The method includes: generating a parity according to first data. The method also includes: when programming the first data into first physical programming unit, programming at least one mark into redundancy bit area of the first physical programming unit. The method further includes: programming the parity into at least one second physical programming unit arranged after the first physical programming unit, and the at least one mark indicates that the parity is programmed into the at least one second physical programming unit.