This document summarizes a study that investigated the effect of adding silica fume and basalt fiber on the properties of black cotton soil. Laboratory tests were conducted on soil samples with 0-20% silica fume and 0.05-0.2% basalt fiber by weight. Tests showed that both additives significantly changed the soil's consistency limits and improved compressive strength. Specifically, the addition of basalt fiber provided better compressive strength gains compared to silica fume. The study aims to evaluate these additives as potential soil stabilizers to improve black cotton soil properties for construction.