Rainfall has been recognised as the dominant trigger for most landslides in the world. Reduction of shear strength due to loss of suction is the main cause for shallow landslides where soil is in unsaturated state. The current research shows that the shear strength of unsaturated soil can be predicted by various soil parameters. The purpose of this research is to examine the influence of water in the shear strength of unsaturated soil and develop an effective model for the prediction of shear strength. Direct shear tests on the remoulded samples revealed that shear strength reduces as the moisture content increases. The soil behaviour in low suction range (0 to 500 kPa) is important for geotechnical structures. The suction test using filter paper technique indicated that tested soils exhibit low suction range, when the moisture content varies from 10% to 51%. Prediction of shear strength of unsaturated soils was carried out with two published equations and one proposed simpler equation.