The physical and mechanical properties of one year to five years old muli and borak bamboos have been studied. The moisture content and the shrinkage change significantly along the culm height. The age has substantial effect on these properties for borak, but not for muli. Specific gravity differs considerably with height and age. Mechanical properties have also changed with age and height position. Both the species have been found to attain maturity in respect of specific gravity and bending strength at the age of three years.