The purpose of this research is to investigate success factors of knowledge management in Korea companies. The research scheme was experimented through a questionnaire survey answered by 87 companies. The research model was composed of five groups : 1) CEO support and business strategics, 2) organization culture 3) information technology characteristic of knowledge workers 4) a reward and performance measurement 5) knowledge management system. The results of this research indicated that the CEO support and organization culture are important factors for knowledge activities. The information technology characteristic of knowledge workers and a reward have small effects for knowledge activities. Manufacturing companies and non-manufacturing companies need different knowledge management strategies. The results of this study will be helpful for the success implementation of knowledge management in Korean companies.