Knowledge Management (KM) is the process of system identification, acquisition and transfer of information and knowledge that people can use to create for perfect competition. KM is considered as an intellectual property of opinions in favour of social orientation and it is created in organizations through social relationships. The definition of KM highlights that it could be considered as closely related to the theory and practice, and is a highly interdisciplinary field of multi-disciplinary. The purpose of this paper is associated with the knowledge management in general and uses survey in Vietnam companies and universities to analysis the role of knowledge management for business development. The authors collected data from 300 companies and universities in Hanoi, Danang, Ho ChiMinh and Can Tho cities. The descriptive statistics, Cronbach Alpha test, Exploratory Factor Analysis, Confirmatory Factor Analysis and Structural Equation Modelling methods were used in this paper. The results indicate that KM had a positive impact on the efficiency of the business organizations. The study also shows that there was a big difference on the effect of KM on organizational effectiveness in terms of SMEs and large enterprises.