A multilevel modulation optical transceiver for distributing an OTN frame defined by ITU-T to a plurality of lanes for transmission, the multilevel modulation optical transceiver including: an MLD transmission unit; and a data replication unit, further including a data rearrangement unit arranged at a preceding stage of the MLD transmission unit, for performing data rearrangement processing of replicating, in advance, a frame synchronization pattern of an overhead of the OTN frame before being subjected to the lane rotation processing from a first lane that has the overhead to another lane that does not have the overhead, and of saving a payload to be overwritten with the frame synchronization pattern to a reserved area of the overhead to enable the payload to be restored on a reception side.