An ambient humidity control article for controlling the ambient humidity within 45%-55%. The article includes a substrate having a predetermined water absorbability, and a humidity control layer coated on the substrate. The amount of the composition coated on per cubic centimeter of the substrate is 0.54-0.74 grams. The composition includes at least one organic acid salt, at least one polyol and water. The count of carbon in the polyols is not greater than 5. The weight percentage of the organic acid salt and the polyols in the composition is 30.6%-58.8% and 9.3%-26.7%, respectively. The water absorption amount of the substrate is not less than 0.5 grams per cubic centimeter. The article can control the ambient humidity without the need to pre-adjust the objective space. The article has a large capacity of moisture absorption and desorption, and can quickly achieve the desired humidity.