In today's knowledge era, knowledge management is increasingly considered the best strategy for improving the labor productivity of an enterprise. However, the effectiveness of KM on labor productivity is not known exactly. Despite the growing interest in KM research, there are knowledge gaps, especially in the context of a developing country like Vietnam, in implementing a KMS successfully for improving the labor productivity. So, it is necessary to do research on this subject. Besides, the labor productivity of Vietnam is currently at a very low level. It requires a new management method for improving the labor productivity for sustainable development towards a knowledge society. In order to successfully implement a KMS, a technology readiness, especially ICT maturity, is a requisite. Recently, SNS has been considered not only a popular technique for communication and collaboration, but also a suitable platform for implementing KMS. Therefore, this research tries to apply KM based on SNS to improve the labor productivity of Vietnamese enterprises, especially SMEs, because of its important role.