In Japan there are a problem of disposing space and a problem，it is necessary to consider the recycling method of a disposal plastic years. In the present condition，the recycling of waste depends on reclamation，due to its low saturation level. In order to over come such a problem，it is necessary to consider the recycling method of disposal plastic. One of the methods for recycling plastic waste is by mixing it with Masa for the purpose of ground stability. This paper considers the reduction of the reclamation places by using the plastic waste as a mixing with conventional construction materials. It inquires about use for engineering-works materials especially this time. A waste plastic is mixed in the Masa，the adhesion effect of the scarce Masa is raised to adhesiveness from various soil examination，and it aims at examining the effect as the stable processing ground experimentally.