In this research, the physical properties and stress paths of commercially available Malaysian kaolinite silts have been made available for laboratory testings. Properties and behavior of the kaolinite silts with varying clay contents have been studied in terms of particle size distribution, Atterberg limits and consolidated isotropic undrained (CIU) triaxial tests. Through understanding the physical and mechanical properties of the kaolinite silts, the results will form baseline data for the study of riverbank soils of Sarawak, which are dominated by similar high plasticity soft silts. Linear but inversely proportional relationships have been established between the effective angles of internal friction and the Atterberg limits. Hence, the designers may use the established equations to estimate the preliminary effective angle of internal friction if the only available data is Atterberg limits.