Objective To prepare low molecular weight Eucheuma striatum sulfated polysaccharides. Methods Eucheuma striatum sulfated polysaccharides were degraded with hydrogen peroxide under the ultrasonic wave. Molecular weight and the content of sulfate radical, 3,6-anhydro-galactose of all sulfated polysaccharides were determined. Results The polysaccharides with molecular weight from 5000 to 40000 were prepared and the content of sulfate radical was above 18.5%. Conclusion This method is fit for preparing low mole...