Researching, building and implementing the knowledge management systems are becoming an effective competitive strategy for each enterprise. However, to develop system well, the authors need to identify clearly the elements affecting the system. For solving this problem, the article mentions about the influence of the elements forming knowledge management system of small and medium-sized enterprises in Thai Nguyen city. Data were collected through the survey by questionnaire, and to be answered on the Internet by employees in small and medium enterprises in Thai Nguyen city.