Lao PDR is a land-locked country surrounded by neighboring countries including Thailand, Vietnam, Cambodia, Myanmar, and China. Due to its geographic location, it has been a vision of Lao Government to develop road infrastructures and become a land-link country. There are obstacles, however, in extending the road network infrastructure development plan, one of which is to ensure sustainable infrastructure development. For many years, the Government of Lao PDR extends national road network to reach this vision. The human resources necessary to realize this development plan, however, are still not met. As such, international training transfer is viewed as one key element to address human resource deficiency to improve infrastructure development in Lao PDR. In this vein, Non-Government Organization (NGO) funding supports were secured and oversea training programs have been engaged. In the case of oversea training program, trainees are expected to transfer their knowledge on road asset management to contribute to the required critical number of human resources. Therefore, it becomes necessary to make clear the effectiveness of these training programs for sustainable development. This research, taking Lao PDR as a case study, aims to identify the influence of factors that affect the training transfer of trainees after they joined the Improvement on Road Management Capability training in Japan and Thailand between 2012 and 2017. An initial qualitative survey by personal interview was conducted by face to face interview with observation during discussion. The interviewees at least joined external training program once and are coming from six departments relevant to the project under Ministry of Public Works and Transport (MPWT). The results from these interviews are beneficial for classifying the affecting factors of the training transfer on the sustainable road infrastructure development plan for Lao PDR.