This research is a study of the concrete block production. The purpose is to study the appropriate ratios to produce concrete blocks with a mixture of rice straw and rice husk ash with cement Portland and the sand is an ingredient be molded by hand. Size 20x100x20 mm. curing time is 7 days andtake samples to test the physical properties. Found that the ratio of the rate of water absorption the modulus of the fracture through benchmark of TIS 58 the change in length is not able to pass the benchmark