With respect to a coherent optical receiving apparatus, a polarization multiplexing light signal, whereupon a first signal is placed upon a first polarized wave light and a second signal is placed upon a second polarized wave light, is polarization divided upon the transmitting side thereof, and the first signal and the second signal cannot be received in correspondence with the transmitting side. Accordingly, disclosed is a coherent optical receiving apparatus, comprising a coherent light receiving unit that detects coherent light, and a signal processing unit that carries out signal processing that is set with control coefficients. The coherent light receiving unit receives a first polarized light that is modulated with a first transmitted signal and outputs a first detected signal, and simultaneously receives the first polarized light with a second polarized light that is modulated with a second transmitted signal, and outputs a second detected signal. The signal processing unit establishes a first control coefficient on the basis of the first detected signal, and establishes a second control coefficient on the basis of the first control coefficient and the second detected signal, and employs the second control coefficient to output a first received signal corresponding to the first transmitted signal, and a second received signal corresponding to the second transmitted signal.