in civil engineering concrete is a material combined of hydraulic cement, sand, gravel and water. gravel and sand compose 60 to 70 percent of concrete. these aggregates support compression force of concrete. cement paste acts as glue to stick grain together. in bushehr factories producing aggregates do not operate according to astm standards, so that fineness modulus (fm) of the produced sands is 3.6 (recommended astm range for fm is 2.3 to 3). the purpose of this study is to improve sands grading, using aalishahr dune sands, 30 kilometers away from bushehr. different percentage of aalishahr dune sands replaced factory sands and concrete was made according to every percentage of replacement. the result indicate that according to slump test, increasing aalishahr dune sands workability of the fresh concrete increases, too. also increase in compression stress is due to 20 percent replacement of sands, causing 20%in 7 days, 18% in 28 days, 31% in 90 days concrete samples, compared to samples without aalishahr dune sands. the minimum of water absorption was in hardened concrete with 10 to 20 percent of aalishahr dune sands.