During past two decades researches have done intensive research on adoption of different types of information technology using different research models. The adoption of enterprise resources planning systems is often investigated using TAM approach via numerous studies. Pasaoglu26 performed the research based in Turkey using demographics, knowledge about ERP, organizational culture, perceived ease of use and actual use of ERP system. Main findings indicated that ERP is also a social system in addition to being technical and that Turkish companies in general want to implement ERP. Kwak et al.19 used TAM in project based sector and found out that consultant support on PU was negative. They extended TAM in terms of implementation projects, internal and external support and functionality selection. Money and Turner24 have used TAM approach to study adoption of knowledge management systems and found that relationships between perceived ease of use, perceived usefulness and system usage were consistent with earlier findings. They also stated that this study provides preliminary evidence that previous information technology acceptance research based on the TAM, may serve as a foundation for research of knowledge management system user acceptance.