Aquaporins are small membrane proteins which their molecular weight is approximately 30 KDa. Aquaporins family has 13 members. Aquaporins transport the water through the membranes. Some of them also transport polar and small substances such as glycerol and urea. Aquaporin-7 is most abundant in adipose tissues. There are increasing evidences about the relationship between aquaporin-7 deficiency and obesity. In this review, the structure, functions and regulations of aquaporins and also its relationship with obesity were evaluated.