This research reports the reduction of water absorption and density increase of kapok fibers from production centers in Pati, Indonesia. Kapok fiber was treated with two solvents, hexane and NaOH solution at room temperature. The NaOH solution was used in five different concentrations; 3.5, 7, 10.5, 14, and 17.5%. Fiber morphology, water absorption, density, and weight loss were determined. Results indicated that the average diameter and fiber length obtained was 70.97 µm and 2.3 cm, while its cellulose and lignin contents were 55.69% and 20.56%, respectively. Furthermore, there was no significant difference between treating kapok fiber with hexane and with NaOH solution. The 17.5% NaOH solution treatment reduced water absorption, increased density, and reduced weight losses by 55.98%, 255.55%, and 25.58%, respectively.