Abstract: Objective: To discuss the effect of extract of Ardisia crenata var. bicolor on proliferation and apoptosis of breast cancer cells and its molecular mechanism. Methods:Breast cancer cells MDA-MB-453 were divided into the control group,the groups of extract of Ardisia crenata var. bicolor of low,medium and high dose,the extract of Ardisia crenata var. bicolor +pcDNA3.1 group,and the extract of Ardisia crenata var. bicolor +pcDNA3.1-MNX1-AS1 group. The inhibition rate of cell proliferation was tested by methyl thiazolyl tetrazolium assay method. The colonly forming ability of cells was tested by colony formation assay. Cell apoptosis was detected by flow cytometry. Cell migration and invasion was detected by Transwell method. The expression level of MNX1-AS1 was detected by quantitative real- time PCR. The protein expression of cyclindependent kinase inhibitor 1A(P21),cysteinyl aspartate specific proteinase-3(Caspase-3),Epithelial-cadherin(E-cadherin), and matrix metalloproteinase- 2(MMP- 2) was detected by Western blot method. Results: Compared with those in the control group,in the groups of extract of Ardisia crenata var. bicolor of low,medium and high dose,the inhibition rate of cell proliferation,the apoptosis rate,and the expression levels of P21,Caspase-3 and E- cadherin were increased(P<0.05). Compared with those in the control group,in the groups of extract of Ardisia crenata var. bicolor of low,medium and high dose,the number of cell clone formation,migration and invasion,as well as the expression levels of MNX1-AS1 and MMP- 2 were decreased(P<0.05). Compared with those in the extract of Ardisia crenata var. bicolor + pcDNA3.1 group, in the extract of Ardisia crenata var. bicolor +pcDNA3.1-MNX1-AS1 group,the inhibition rate of cell proliferation,the apoptosis rate,and the expression levels of P21,Caspase-3 and E-cadherin were decreased(P<0.05). Compared with those in the extract of Ardisia crenata var. bicolor +pcDNA3.1 group,in the extract of Ardisia crenata var. bicolor +pcDNA3.1-MNX1-AS1 group,the number of cell clone formation,migration and invasion,as well as the expression levels of MNX1- AS1 and MMP-2 were increased(P<0.05). Conclusion:Extract of Ardisia crenata var. bicolor can inhibit proliferation,migration and invasion of breast cancer cells MDA-MB-453,and promote cell apoptosis. The mechanism may be related with MNX1-AS1.