Abstract: Iron ore tailings sand (IOTS) was used to prepare cement mortar by replacing nature river sand, and mortar properties such as strengths and durability were texted. The results show that apparent density, compressive strength and elastic modulus of IOTS mortar made by the same mix proportion are greater than that of nature river sand mortar except for lower fluidity. Size expansion of IOTS mortar occurs compared to size shrinkage of nature river sand mortar under water curing, however significant size shrinkage occurs to both of mortars under natural drying. IOTS mortar can stand deterioration of 50 freeze-thaw cycling and have great acid-alkali corrosion resistant. With increasing of magnetic granules content in IOTS, mechanical properties of mortars in early period increase, but 28d strength of mortars decreases. IOTS mortars excluding all magnetic granules are advantageous to the mechanical property due to high amount of harmless pores at 28 days.