This study aimed to analyze and understand work practice of museum educators in adapting constructivist
museum education which overthrows traditional practices of museum education in many ways, yet has
been regarded as main stream of museum education. For the purpose, Cultural-Historical Activity
Theory(hereafter, Activity theory) has been utilized as a framework to analyze data collected for this study,
and to offer a understanding of the whole work activity of the museum educators. Data collected from deep
interviews with 4 constructivist museum educator selected were analyzed using Nvivo11 and categorized
according to analytic components of the Activity theory. The results showed contradictions and tensions,
which occur within multiple interrelated activities to implement constructivist museum education by the museum
educators. Yet, the educators tried hard to overcome the challenges by their practice. Such efforts
by them would come to the terms of evolution of the museum education community over all. On the top
of that, this study clearly presented the Activity theory as an useful tool to understand and present a professional
work practice such as museum education field.