Objective：To investigate the in vitro effects and the primary mechanisms of Changweiqing（肠胃清, CWQ）on antimetastasis and antiinvasion of hypoxic colon carcinoma cells.In addition,to provide experimental evidence for the Chinese medicinal theory of＂strengthening the body＇s resistance to eliminate pathogenic factors＂in the treatment of colorectal cancer,including its invasion and metastasis.Methods：First,CWQ sera were prepared with serum-pharmacology methods.Then,the modified hypoxic chamber was designed and flushed with 5%CO_2 and 95%N_2 at 37℃to induce a hypoxic environment.The effect of CWQ serum on the viability of LoVo cells was tested with MTT cytotoxicity assay.The wound model and chamber model were established to estimate the effects of CWQ serum on migration and invasion of LoVo cells.The model for cell adhesion was established to evaluate the effect of CWQ serum on LoVo cells＇ adhesion.The gelatin zymography model was performed to determine the effects of CWQ serum on the activities of matrix metalloproteinase-2 （MMP-2）and matrix metalloproteinase-9（MMP-9）.The effects of CWQ serum on the hypoxia-inducible factor 1α（HIF-1α）nuclear translocation and the mRNA level of vascular endothelial growth factor（VEGF）in LoVo cells were determined by Western blot and reverse transcription-polymerase chain reaction（RT-PCR）analyses, respectively.Results：CWQ inhibited LoVo cells＇ migration based on wound healing assay.The inhibitive effect could reach about 68.00%under hypoxic culture and about 29.87%under normoxic culture when cells were treated with 10%CWQ serum for 24 h.The results from both cell invasion and adhesion assays showed that CWQ serum could dose-dependently repress the invasion of LoVo cells and inhibit cells from adhering to extra cellular matrix（ECM）.Under the hypoxic culture condition,RT-PCR analysis showed that 10%CWQ serum had down-regulated the expression of VEGF by 45.87%,and the result of Western blot analysis provided further evidence.The HIF-1α
