A biodegradable resin composition containing a biodegradable resin and a cellulose having a crystallinity of X (%), wherein the cellulose is obtained by a step including subjecting a cellulose-containing raw material to a pulverization treatment (A), wherein the cellulose-containing raw material contains a cellulose having a crystallinity of Y (%), and has a bulk density of from 100 to 500 kg/m3, and an average particle size of from 0.01 to 1.0 mm, and contains a cellulose in an amount of 20% by weight or more of a residue component obtained by removing water from the raw material, wherein X and Y satisfy the following formulas: 50≦X≦Y−5 (1) and 55≦Y≦99 (2). The biodegradable resin composition can be suitably used for various industrial applications, such as daily sundries, household electric appliance parts, and automobile parts.