The total polysaccharides from Taxus mairei were pretreated by ultrafiltration to remove pigments and the operating condition was optimized as follows:molecular cut-off 5 k Da,temperature 25℃,operating pressure 20 psi and p H6.8. Under the aforementioned condition,the 1L solution containing 10g/L total polysaccharides was ultrafiltrated to 125 m L first,then deionized water was added into condensed solution to 1L total volume and was repeated 4 times,respectively. The results showed that the retention rate ...