The aims of the research is to empirically study the full-time faculties of private universities perceptions on the influence of organizational culture and motivation on organizational commitment and its implication on job performance. The research design used quantitative approach through research instrument. The unit of analysis in this study was full-time lucterers at private universities in the South Sumatera province. The data were gathered through face to face distribution by the researcher. Purposive sampling was used to collect sample of this research. The total respondents under this study were 245 who were selected form 1,996 faculties of all private universities in the South Sumatera Province. To analyse the proposed hypothesis, this research employed Structural Equation Model (SEM) operated with Lisrel 8.0. This research indicated that organizational culture and work motivation have a positive effect towards organizational commitment. These empirical research findings have also shown the significant positive effect of the organizational commitment towards job performance. It is also proven that organizational commitment has taken a mediating role on the influence of organizational culture and work motivation on job performance.