Black cotton soil is known for its expansive properties, which can lead to infrastructure damage and instability. Biochar, a carbon-rich material derived from the pyrolysis of organic matter, offers a renewable and cost-effective alternative to conventional stabilizing agents. This study investigates the potential of biochar as a sustainable and eco-friendly solution for improving the engineering properties of black cotton soil, known for its high shrinkage and swelling characteristics. The objective of this project is to determine the optimal dosage of biochar for enhancing the physical and mechanical properties of black cotton soil. Laboratory testing, including heavy compaction test, unconfined compression test (UCS), specific gravity, and ++ centages of biochar (2.5%, 5%, 7.5%, and 10%). The results demonstrate that the addition of biochar significantly improves soil stability and reduces shrinkage and swelling geotechnical properties. The findings of this research provide valuable insights for soil stabilization practices in regions where black cotton soil is prevalent. The study highlights the potential of biochar as a sustainable solution for enhancing the engineering properties of black cotton soil, contributing to the development of environmentally friendly soil stabilization techniques.