Carbon growth site on the surface of a solid oxide fuel cell (SOFC) comprising yttria stabilized zirconia (YSZ) and Ni was observed using transmission electron microscopy (TEM). TEM observations of the YSZ and Ni powder mixture, which was heated in a methane atmosphere, confirmed that graphite was grown on the Ni surface only, and not deposited on the YSZ surface or the interface between YSZ and Ni. Additionally, the grown graphite was confirmed to have a curled structure and to terminate growth at the Ni-YSZ interface. These phenomena were likely caused by differences in the carbon wettability against Ni or YSZ, as well as oxygen diffusion from YSZ to Ni.