Bagasse is a solid waste from the sugar cane milling process in the sugar industry. Bagasse contains lignin, cellulose and hemicellulose, which through the fermentation process by Phanerochaete chrysosporium can produce crude cellulase, furthermore cellulase and other enzymes can be used in bagasse fermentation to produce bioethanol. The purpose of this study was to determine the effect of fermentation time and the addition of crude cellulase to the yield and concentration of bioethanol produced in bagasse fermentation. The research was carried out with the stages of the process: Preparation of raw materials (bagasse), Preparation of crude cellulase, Fermentation process, Product analysis (Bioethanol). The variables used in the experiment were fermentation time (96, 120, and 144 hours) and the addition of crude cellulase (10%, 20%, 30%, 40%, and 50% (v/v)). Analysis of crude cellulase activity using the DNS method, while the analysis of bioethanol concentration using the chromatography methods. The results showed that the maximum yield was 16.24% and the highest bioethanol concentration of 11.04% was obtained at the time of fermentation of 144 hours and the addition of crude cellulase by 50% (v/v).