Fruits and vegetables are an important part of the human diet. The health effects of fruits and vegetables are closely related to human health. Polysaccharides are the main active components of fruits and vegetables， and immune regulation is their main effect. It is of great significance to clarify the immunomodulatory activity and mechanism of fruit and vegetable polysaccharides. This article reviewd the structural characteristics of fruit and vegetable polysaccharides， and their immunomodulatory effect and mechanism. The future research direction of the structure analysis of fruit and vegetable polysaccharides and their structure-activity relationship about immunomodulatory， and their mechanism were also prospected.