OBJECTIVE： To establish a method for the dissolution determination of Pentoxyverine citrate and guaifenesin tablets， and to compare the difference of preparations from different manufactures. METHODS： The paddle method was used to determine the dissolution， using water as medium with medium volume of 1 000 mL and rotation speed of 75 r/min，sampling at 45 min. HPLC method was used to determine the accumulative dissolution of pentoxyverine citrate and guaifenesin： CAPCELL PAK C18 MGⅡ S-5 column； mobile phase of acetonitrile-triethylamine phosphoric buffer solution（pH 2.6±0.05）（33 ∶ 67，V/V）， flow rate of 1.0 mL/min， detection wavelength of 215 nm （pentoxyverine citrate） and 275 nm （guaifenesin）， column temperature of 35 ℃， sample size of 20 μL. RESULTS： The linear range of pentoxyverine citrate and guaifenesin were 5.091 6-50.915 5 μg/mL（r＝0.999 9） and 29.999 5-299.995 2 μg/mL（r＝0.999 9）， respectively. RSDs of precision， stability and reproducibility tests were all lower than 2.0％. Average recoveries were 97.90％-100.68％（RSD＝0.95％，n＝9） and 97.09％-101.85％（RSD＝1.32％，n＝9）.  Average accumulative dissolution of  pentoxyverine citrate in 6 manufactures of samples were 12％， 98％， 66％， 97％， 91％， 32％（n＝3）； those of guaifenesin were 8％， 95％， 68％， 90％， 93％， 18％（n＝3）， respectively. CONCLUSIONS： The method is simple， accurate， sensitive， specific and suitable for the dissolution determination of Pentoxyverine citrate and guaifenesin tablets. The dissolution of samples between different manufactures and the same manufactures different batches are quite different.