Objective TP53 is an important tumor suppressor gene, however, mutations of p53 occur in over 50% of all cancers and are indicative of highly aggressive cancers that are hard to treat. Targeting mutant p53 (mutp53) is one of the effective strategies in cancer therapy.Methods We constructed a high throughput screen system which contains the p53 targeted puma, H1299-p53R273H-PUMA-luciferase, and H1299-p53R175H-PUMA-luciferase to screen compounds targeting mutp53. Using immunofluorescence assay to detect the effect of andrographolide on the expression of mutp53 in HT29 (R273H) and SK-BR-3 (R175H) cells. Western blotting experiment and qRT-PCR analysis were used to further observe the protein and mRNA expressions of andrographolide on p53 downstream target genes PUMA, p21, and Noxa in mutp53 tumor cells. Then MTT and flow cytometry were used to detect andrographis paniculata The effect of lactone on tumor cell proliferation and apoptosis. In addition, after knocking down Hsp70 expression by siRNA, the reactivation effect of andrographolide on mutp53 downstream genes was also studied.Results Andrographolide enhanced PUMA-luciferase expressions in both cell lines. Andrographolide could reduce the expressions of mutp53 in HT29 (R273H) and SK-BR-3 (R175H) cells, while the expressions of wild-type p53 increased by immunofluorescence assay. Andrographolide can inhibit the cancer cell proliferation and induce apotposis in mutant p53 cancer cells. Andrographolide can enhance the p53 downstream target protein and mRNA expressions of PUMA, p21, and Noxa. Andrographolide increased the expression of molecular chaperone Hsp70 in HT29 and SK-BR-3 cells, as the chaperones play important role in p53 structure function, we knocked down Hsp70 by siRNA and found that the upregulation of p53 targeted genes was reversed.Conclusion Andrographolide restores the wild-type-like p53 function dependent on Hsp70.