With more and more people paying attention to substantial democracy, participatory democracy is presented as a practical strategy and an index of Korean democracy. In this social and political atmosphere, participation in environmental planning and design is essential. Nonetheless, the true meaning of “participation” is not used properly because many people do not understand it correctly, The concept of social and political participation is “the action or attempt of ordinary members of society for affecting on the result of decision making.” Based on this concept, participation is accomplished through conventional means and as a form of mobilization in environmental planning and desist Most of the theories on public participation in landscape architecture are technical theories. Therefore, this paper proposes that planning and design of landscape architecture be understood as a communicative action that aims to enable stakeholders to reach a consensus through communication. This study offers the framework of theory to understand and practice planning and design of landscape architecture as a communicative action, after reviewing communicative action theory and communicative planning theory. Results suggest that communicative action theory should be accepted in landscape architecture to overcome the shortcomings of instrumental rationality -- the same way planning theory accepted this theory --and to join the culture of experts focusing on the artistic truth and the culture of life of the world. In addition, accepting communicative action theory enables the acquisition of the instrumental effect and social learning effect and the making of social capital. This study also suggested prerequisite for using the method. There should be change in the social institution and in individual action. In addition the method is composed of three steps: creating the atmosphere for communication; communicating, and; reaching a consensus among stakeholders. Finally, raising the possibility of applying the theory presented in this study requires the accumulation of know-how through trial and error.