Objective: To investigate relationship between osmosis pressure and conductivity of Chinese medicine decotion

and construct model of them. Method: This model was based on the concentration of decotion

which had a postive effect on osmosis pressure and conductivity in some degree.There were 25 system to research relationship between osmosis pressure and conductivity.Rationality of the model was verified by taking Gardeniae Fructus decotion and Liuwei Dihuang Wan decotion as experimental subjects. Result: They had good linear relation in the range of 0.78-7.26 ms·cm-1 of conductivity

the correlation coefficient was 0.964 2.As time went on

the change rule of osmosis pressure and conductivity was similar

in addition

they both had positive relationship with decotion concentration.Fitting equations of Gardeniae Fructus decotion (25-250 g·L-1) and Liuwei Dihuang Wan decotion (25-125 g·L-1) were π=0.088 0e-0.050 1 and π=0.368 4e-0.118 9.These calculated values and measured values were no significant difference. Conclusion: The model of osmosis pressure and conductivity building in this study is proved to be efficient in some degree.It provides a simple

efficient and reliable way to detect osmosis pressure on line in reverse osmosis membrane of Chinese medicine decotion.