A data training method of a storage device, which includes a storage controller and a nonvolatile memory device, includes transmitting a read training command to the nonvolatile memory device, receiving a first training pattern output from the nonvolatile memory device in response to the read training command, receiving a second training pattern output from the nonvolatile memory device in response to the read training command, comparing the received first training pattern and the received second training pattern with a reference pattern, and determining a read timing offset of the storage controller depending on the comparison result.