Noni fruit is believed can increase stamina. The purpose of this study was to prove the tonic effect of noni fruit ethanol extracts (NFEE) to the male Swiss mice and identify flavonoid compound contained in the extract. Noni fruit extracted by the maceration method in ethanol 70%. Identification of flavonoid compound conducted with FeCl3 reagents and thin layer chromatography (TLC). This research is experimentally with pretest-posttest matched control group design. The tonic effect assay conducted with natatory exhaustion method. Twenty-five mice divided into five groups. Mice in group I, II, and III treated with NFEE (160, 400, and 800) mg/kg BW. Mice in group IV treated with caffeine 100 mg/kg BW (positive control) and group V treated with CMC-Na 0.5% 25 ml/kg BW (negative control). The test preparation given for 14 days orally. Data of survival time swam mice before and after treatment analyzed statistically with Wilcoxon test and paired t-test. Data was analyzed for different effect intergroup treatment with Kruskal-Wallis and then with Mann-Whitney at 90% confidence level. The result showed that NFEE (400 and 800) mg/kg BW have a tonic effect (p<0,1). Flavonoid compounds have been found in NFEE.