Biomass fuel such as briquette is one of an alternative energy regarded to the shortage of the fosil fuel and rising its prices. The byproduct of sago starch industry is the waste that remain the environmental problem because of the odor. However this agricultur waste such as trunk cortex and fibre has a potential application as a raw material for briquette.The fibre and trunk cortex act as matrix material of briquette. The utilizing of sago waste as a biomass briquette and the effect of ratio of matrix/binder to the density, time of compustion and gross heat of the briquette have been elucidated sistematically. The analyzing of gross heat using adiabatic calorimetry indicated that the briquette prepared with the ratio of binder/matrix of 3:4 (mass ratio) had the maximum value of 3929.5 kal/g. The duration of combusion was proposional with density of the briquette.