Abstract: The paper focuses on the apparent cohesion of the unsaturated sand. The efforts have been done in the laboratory to use organic materials, clay, and Dutch black peat to improve the apparent cohesion of the unsaturated sands. Five types of sand, organic material, black peat, bentonite and kaolinite have been chosen to probe the cohesive characteristics of sand under unsaturation state. The test results shown that the sand shows some cohesion under unsaturation state and some material shows a significant increase in apparent cohesion of unsaturated sand.