Various agricultural wastes such as sugarcane bagasse, wheat and rice straw were utilized for ethanol biosynthesis by the microbial strain Saccharomyces cerevisiae MTCC3821. Application of physical (temperature range from 30 to 120oC with different size of plant biomass with solid ratios) and chemical agents (acidic solution~1.92M to 3.0M; or alkaline solution ~0.125 M to 0.8M) alone or also in combined forms were applied to make effective hydrolysis of plant wastes. Good biomass hydrolysis was obtained at a combined effect of temperature of 120oC and sodium hydroxide (0.25 M) or hydrochloric acid (2.5M) solution. Inhibitory compounds which are formed during hydrolysis process are removed by using activated charcoal which in turn increased the production. Various ethanol concentrations (in 1.2 to 1.45 g/L in different biomass hydrolysates and 4.5 g/L or more titer in case of synthetic media) was achieved during fermentation process and S. cerevisiae strain MTCC 3821. It was also observed that ethanol titer depends on feedstock used and also hydrolysis rates of biomasses. This research work results are promising for future researches with promotion to cellulosic ethanol production from cheap agricultural residues. And these waste utilization for this fuel can help to generate revenue to farmers.