This study empirically investigated the effects of both organizational culture(i.e., innovative, supportive and bureaucratic) and information technology(IT) infrastructure(i.e., knowledge storage, transfer and search IT) on the knowledge management(KM) activities(i.e., knowledge creation, sharing and application) in Korean manufacturing firms. We also partially demonstrated the impact of KM activities on the KM performance(i.e., KM satisfaction) of a firm. Through multiple regression analyses, it was found that innovative and supportive culture, and IT infrastructure have a positive impact on the activation of KM activities. The results of this study also showed that the innovative and supportive culture positively influence the adoption of IT infrastructure, and through the construction of IT, they have an indirect effect on KM activities. With a structural equation modeling technique, the causal relationships among organizational culture, IT infrastructure, knowledge management activities, and KM performance were confirmed. Hence, it is concluded that culture and IT infrastructure have direct effects on KM activities, and culture also indirectly influences KM activities through the adoption of IT infrastructure.