The present invention discloses a small molecular polysaccharide with moisturizer and manufacturing method thereof. The manufacturing method comprises the following steps: extracting mushroom-like to obtain an abstract. The abstract is precipitated for obtaining a polysaccharide, and then a compound is generated by adding hydrolase or acidic solvent into the polysaccharide. By conducting hydrolysis and freeze-drying of the compound, the small molecular polysaccharide is obtained. Wherein, the mushroom-like comprises a Xylaria nigripes and the molecular mass of the small molecular polysaccharide is less than 30k Dalton and larger than 3k Dalton.本發明揭露一種具有保溼功能之小分子多醣體及其製造方法,其製造方法包含以下步驟:藉由將菇蕈類進行一萃取以得到初萃物。利用澱析程序使初萃物析出粗多醣。以及添加酸性溶劑或多醣水解酵素於粗多醣以形成混合物,並將混合物進行水解程序及冷凍乾燥程序以得到小分子多醣體,其中此菇蕈類係包含一烏靈參且此小分子多醣體之分子質量係介於3k~30k道爾頓(Dalton,Da)之間。S1~S3‧‧‧步驟
