The objectives of this research were: 1) to investigate the elements and indicators of collaborative leadership of primary school administrators, 2) to explore the existing situation and required situation of collaborative leadership of primary school administrators, 3) to develop a program to enhance collaborative leadership of primary school administrators, and 4) to investigate the effect of development for collaborative leadership of primary school administrators, from the usage of developed program. Research and Development (R&D) was employed which designed 4 stages, a sample group of 753 primary school administrators and teachers, chosen by multi-stage sampling, gave quantitative data; and experts purposively chosen were asked to provide qualitative input. The statistics used in this research included the percentage, mean, standard deviation, the Priority Need Indicator (PNI [subscript Modified]), and Dependent t-test. The results found that 7 elements 65 indicators. The training program which was developed and reviewed consists of four modules: Module 1, Characteristics of trust and commitment; Module 2, Paradigms of shared vision and collective decision making; Module 3, Skills in transforming change, risk taking and conflict management; Module 4, Assessment and reflection on collaborative leadership influences in fulfilling duties. In the implementation of the training program for 12 weeks employing 8 training kits, the 30 primary school administrators who volunteered to join significantly improved their test scores after the training and felt very highly satisfied with the program. In addition, the collaborative leadership of primary school administrators posttest was at higher level than the pretest at 0.01 level.