Sesbania gum (SG) was subjected to chemical modification via the first acidolysis followed by cross-linking under maintaining the basic framework of SG particles so that its performances could be well tailored. The modification of SG was preferred for food processing and drug sustained-release agent uses. The experimental results indicated that the size distribution of SG particles was slightly narrowed by the acidolysis, while the size distribution was apparently broadened by cross-linking. More interestingly, the acidolysis evidently enhanced the intensity of hydrolysate at diffraction angle of 14.5°. The cross-linking was able to improve the freeze-thaw stability, acid and alkali resistance of SG, while the acidolysis only improved the acid resistance. As a traditional role, the cross-linking could lead to the reduction in the swelling capacity of SG. The acidolysis and cross-linking raised the thermal stability of SG. The flattened peak of hydroxyl groups confirmed that the cross-linking groups were successfully introduced into the molecular chains of SG according to FTIR. The addition of SG, PHSG, CLSG and CLPHSG as additives could effectively influence the pasting behavior of potato starch.