We investigated the 4H-SiC C-face MOS interface properties around valence-band, and fabricated 4H-SiC C-face p-channel MOSFETs for the first time. For C-face p-channel MOSFETs, relatively low-temperature wet-gate-oxidation was preferable. Post-deposition-annealing for contact metal was found to degrade the C-face MOS interface around valence-band. Low-temperature (800°C) PDA in hydrogen including ambient was effective to some extent in order to suppress the degradation owing annealing. We obtained C-face p-channel MOSFET with normal FET operation by utilizing 900°C wet-gate-oxidation and 800°C PDA in He-H2 forming gas ambient.