A method, an apparatus and a computer for data operation are provided. The method includes: determining, when writing data to a sector of a storage device, whether the sector belongs to an old block for a restore point of the storage device. If so, the method further includes: allocating a new block and writing the data into the new block; creating a table including an address of the old block, an address of the new block and a first identifier, wherein the first identifier has first identification elements corresponding to the sector in the old block and in the new block, respectively, and wherein each of the first identification elements has a first state indicating to read data from the old block during data restoration in the sector and a second state indicating to read data from the new block during data restoration in the sector; and pointing the address of the old block in an address index table for the restore point to the created table. Otherwise, the method further includes: allocating a new block and writing the data into the new block; and modifying the address of the old block in an address index table for the restore point into the address of the new block. With the present invention, the time required for operation on the sector for the restore point of the storage device can be saved, and the performance of the computer can be improved.