This book explores the stabilization of black cotton soil using biodegradable polythene as a sustainable alternative to conventional methods. Black cotton soil is known for its high swelling and shrinkage properties, posing challenges for construction. By incorporating biodegradable polythene strips, this study aims to enhance the soil's geotechnical properties while addressing plastic waste. Experimental results indicate that adding polythene significantly improves shear strength, bearing capacity, and compressive strength. The optimal polythene content was determined to be 2% by weight of the soil, yielding the best performance in terms of California Bearing Ratio (CBR) and load-carrying capacity. This study demonstrates the potential of biodegradable polythene as an effective, eco-friendly solution for stabilizing black cotton soil, contributing to sustainable construction practices and offering a dual benefit of managing plastic waste while improving soil stability.