The purposes of this research were 1) to study on the development of Knowledge Management in Forensic Computer, and 2) to create of Knowledge Management in Forensic Computer. The study was conducted by both qualitative and quantitative method. In-depth interview was employed as a tool for qualitative method by using 10 experts with high level of education and experiences in evidence investigation and also people who had the cases involved in Forensic Computer. In quantitative method, data were collected by questionnaires from 340 samples of metropolitan police officers from Division 1 to 9 and police officers who their works concerned directly with the evidence investigation for Forensic Computer. Such data were analyzed by descriptive statistics together with a structural equation program to test the model of variables mentioned above. According to the study, it was found that 1) there were 4 important items to be complied in order to develop the evidence investigation system for Forensic Computer. Those were completeness of the evidence, identification of evidence sources, and expertise in collection of evidences, and investigation of evidence by rules of law, respectively; and 2) the analysis of relationship of variables involved in the efficiency of Forensic Computer by the structural equation modelling showed the goodness of fit index in accordance with the relationship of all variables. The result of both qualitative and quantitative methods indicated that technology, work experience, tool and equipment, and evidence collection had the effect on the efficiency of Forensic Computer.