Many buildings face some problems due to the seepage of waste water through the soil under or around the foundations because the waste water contains many injurious chemical materials. The paper presents an experimental study to investigate the effect of addition of different percentages of waste water to the soil. Five samples of fine-grained soil are mixed 0,25,50,75 and 100 percentage of waste water. The mixtures are tested at variable times. Atterberg limits, plasticity index and specific gravity for each mixture are determined. The influence of waste water on the index properties of fine-grained soil is analyzed. The experimental results show that the waste water has undesirable effect on the index properties of fine-grained soil. Liquid limit, plastic limit, plasticity index shrinkage limit increase with increase the waste water in soil, while specific gravity decreases