Objective To investigate the pharmacokinetics of D-polymannuronicate after single and successive administrations for 7 days by means of intravenous injection and intragastric administration.Methods Bioanalysis for the determination of D-polymannuronicate plasma concentration was applied in rats,and parameters of pharmacokinetics were calculated by DAS2.1.1 software.Results The well linearity(r=0.9991) in 0.05～150mg?L~(-1) of plasma concentrations.The recovery rate was between 94.72%～103.21%,the derivations withinday and between-days were less than 15%.Zata were 0.89,1.06,0.93,0.85 h~(-1) and t_(1/2z) were 0.78,0.69,0.75,0.87h corresponding with the four methods of administration.The bioavailabilities were 3%～5%.Conclusion The bioavailability was low.The ends of the elimination of two means of intravenous injection and intragastric administration were same. There was no significant difference in pharmacokinetic parameters of single and successive administrations.