The pharmacological activities of natural glycosides are closely related to the polyfunctional sugar moieties. Modification of active natural products by glycosylation can change the stereochemical configuration, improve the solubility, tune up the activities and change pharmacokinetic properties for higher efficacy and better selectivity. Compared with the common D-glucose, D-allose, a C-3 epimer of D-glucose rarely exists in nature, but it plays an important role in food, health, medicine, and so on. It is not easily metabolized in the living organisms, but can be used as a safe and low-calorie sweetener. The natural allopyranosides are absolute conjugation forms which are same as other glucopyranosides and rhamnopyranosides with a broad array of biological activities. This article summarizes the major progresses made in phytochemistry and biological activity studies of these compounds. Structure-activity relationship analyses of partial anti-tumor and anti-diabetic allopyranosides were performed regarding the data reported in the literatures. These insights may provide a theoretical and experimental reference for the discovery of new drug and drug design based on allopyranosides.