An optical receiver circuit is provided which is able to receive optical signals having a variable transmission rate, without loss of data. The optical receiver circuit according to the present invention has a light-receiving section for converting an optical signal with a variable transmission rate into an electric signal. A recovery section recovers a plurality of different clock signals and data corresponding to possible transmission rates. These data are stored into a plurality of memories and at the same time a decision section decides the transmission rate. A switch section reads data from one of the memories selected according to the result of the decision.