Abstract: After the sample was disolved with a mixed solution with 50 mmol·L^-1 NaH₂PO₄ and 0.1 mol·L^-1 NaCl. The molecular weights of sodium hyaluronate (SH) and sodium chondroitin sulfate (SCS) were identified by gel permeation chromatography combined with multi angle laser light scattering. Then according to the molecular weight distribution of SH and SCS, an analytical column composed of OH pak SB-806 HQ L012028 and OH pak p8514-804 L102028, which were connected in series, and a guard column OH pak SB-G G008146 were used for seperation, with a mixed solution with 50 mmol·L^-1 NaH₂PO₄ and 0.1 mol·L^-1 NaCl for mobile phase at the flow rate of 0.5 mL·min^-1. SH and SCS were simultaneously determined with a differential refraction detector. Linear relationships were found between peak areas and mass concentraions of SH and SCS in the ranges of 0.1-1.0 g·L^-1, with detecion limits (3S/N) of 0.051 g·L^-1 for SH and 0.059 g·L^-1 for SCS. Values of recovery obtained by standard additon method were in the range of 83.3%-110%, and RSDs (n=6) were less than 2.2%.