Red dragon fruit (Hylocereus polyrhizus, (F.A.C. Weber) Britton and Rose) has been reported to have various biological activities such as antimicrobial, anti-hypercholesterolemia, anti-diabetes mellitus, cardiovascular risk reduction, health supplement, and melanoma cell inhibitory. The red thick peel of this fruit is just practically a waste that is possibly utilized to maintain health, therefore this research aimed to isolate and identify active compounds of H. Polyrhizus peels which can improve the immune system of body. In order to simplify methanol extract was partition and fractionation. The active compounds of petroleum ether fraction were separated and purified using preparative thin layer chromatography. The identification of the compounds structure was conducted through spectroscopic techniques, including UV, FT-IR, 13CNMR and 1HNMR spectroscopy. The data of spectra revealed that the isolate is lupeol. The statistical analysis of macrophage activity showed that the isolate with concentrations of 100, 50, 25, 12.5 and 6.25μg/mL could activate the macrophages higher than control negative. Terpenoid generated from the isolation of Hylocereus polyrhizus was identified as lupeol (1-isopropenyl-3a,5a,5b,8,8,11a-hexamethyl-eicosahydrocyclopenya [α] chrysen-9ol. In vitro test shows that the isolated compound had an immunomodulatory activity by increases macrophage phagocytosis of latex beads.