Excess intake of boron containing water can pose serious problems on human beings. Traditional technologies are limited by insufficient efficiency especially for trace boron removal. In this study, a novel sorbent was developed. A series of batch sorption experiments was conducted to investigate the boron sorption behaviors of the synthesized chitosan based sorbent. Our results show, comparing to raw chitosan, the boron uptake capacity of modified chitosan is significantly enhanced and the sorption capacity is determined to be 11.82 mg B/g sorbent. The equilibrium time of boron sorption can be achieved in less than 10 h. At a dose of 1.3 g/L, boron in seawater can be lowered to 0.5 mg/L to meet the WHO standard for drinking water.