The conversion of lignocellulosic biomass to solid biofuel energy and value-added products is globally gaining significant importance. This thesis aims to study briquette production potential as an alternative energy source from water hyacinth and sawdust biomass using waste paper binder for domestic cooking purpose. In this study, the design of the experiment applied was combined optimal design method, and a total of 22 experiments were conducted for mixing ratios (i.e., water hyacinth, sawdust and waste paper) and particle size, three levels, and three replications. The process variable s analyzed during briquetting are average particle size (0.25mm, 1.2mm and 2.4 mm) and mixing ratios (i.e., water hyacinth (50%, 60% and 80%), sawdust (10%, 20%, 30%, 35% and 40%), and waste paper (10%, 15% and 20%)). The response variable is the calorific value of the briquettes. The physical and combustion properties of raw water hyacinth, sawdust and mixed biomass were characterized. The moisture content for raw water hyacinth was 8.67%, 7.65% for sawdust and 7.98% for mixed biomass. The density of raw water hyacinth for 0.25mm particle size was 188.2 kg/m 3 , 95.2 kg/m 3 for 1.2mm and 59.8 kg/m 3 for 2.4mm. Density was significantly influenced by biomass particle size. Carbonization was takes place in a muffle furnace with specified operating conditions: for water hyacinth 425 O c and for sawdust biomass 525 O c, and for both biomasses the carbonizatuion time was 2hours. The physical and compostion parameters of composite briquette including; shatter resisatance, porosity index, water resistance capacity, densisty, relaxation ratio, dimensional stabilility, ash content, volatile matter, fixed carbon, moisture content and heating value were characterized The optimized operating conditions of briquette energy value were 75.5% water hyacinth, 12.34% sawdust, 12.15% waste paper, 0.293mm particle size and the optimized energy value of briquette was 18.038MJ/kg. The addition of sawdust and waste paper with water hyacinth biomass improved the energy efficiency of the composite briquettes by 28.96%. The calorific value of composite briquette was sufficient to produce heat required for household cooking. Key words: Water hyacinth, TGA analysis, Densification, Blending, calorific value