Abstract: Used Artocarpus heterophyllus,Syzygium samarangense,Garcinia mangostana and Annona squamosa as raw materials,the dietary fiber was prepared by chemical binding enzyme method.And used SEM,IR and chemical analysis to study the structural characterization,monosaccharide composition and physical and chemical properties of the prepared dietary fiber. The results showed that:the content of dietary fiber in Annona squamosa was higher,reached(74.31±0.07) g/100 g. The contents of cellulose,hemicellulose and lignin in dietary fiber of four tropical fruits were different. The typical characteristics of polysaccharide in dietary fiber of four tropical fruits were found by infrared spectrum scanning. GC analysis of glyconitrile acetylated derivatives showed that the dietary fiber of four tropical fruits contained rhamnose,arabinose,xylose,glucose,galactose and mannose,and the molar ratio was 1:4.6:6.8:9.4:5.6:3.4(Artocarpus heterophyllus),1:5.9:5.8:4.9:3.9:3.6(Syzygium samarangense),1:4.2:6.1:6.1:2.6:3.1(Garcinia mangostana),5.2:18.9:1:53.4:7.1:7.1(Annona squamosa). Annona squamosa dietary fiber had higher swelling power and cholesterol adsorption(pH2),respectively(21.28±1.15) mL/g,(10.72±0.17) mg/g(pH2),which were significantly higher than those of the other three tropical fruits(P<0.05). The water retention and cholesterol adsorption(pH7)of the dietary fiber of Syzygium samarangense was high,which were(21.90±0.55) g/g,(11.25±0.37) mg/g. Garcinia mangostana dietary fiber had a high oil retention rate of(7.79±0.28) g/g.Scanning electron microscopy morphological characteristics showed that the apparent morphology of dietary fiber of four tropical fruits was significantly different.