Arbutin is a skin-lightening agent that was discovered in berry fruit plants such as bearberry. The Mao tree produces the Mao fruit, which is quite similar to berries. The hypothesis of this research is based on the possibility of the discovery of arbutin in different parts of the Mao tree (Antidesma thwaitesianum Muell. Arg.). The purpose of this research was to determine the presence of arbutin in the unripe fruits (green Mao fruits, GMF), ripe fruits (red Mao fruits, RMF), mature fruits (black Mao fruits, BMF), young Mao leaves (YML) and mature Mao leaves (MML). The arbutin in the samples was isolated by thin layer chromatography (TLC) and quantified using high performance liquid chromatography (HPLC). The results showed that MML contained the greatest amount of arbutin (10.6 mg/100 g of raw material). The arbutin in MML was isolated using solid phase extraction (SPE) and preparative thin layer chromatography (PTLC) and was characterised via ESI-MS. The results of MS confirmed the presence of arbutin in the PTLC extract of MML. The crude and PTLC extracts of MML were tested for inhibitory activity against tyrosinase compared with the arbutin standard. The tyrosinase inhibition activities suggested that IC50 of the crude extract of MML (IC50 = 7.703 mg/l) and PTLC extract of MML (IC50 =9.428 mg/l) were more effective than the arbutin standard (IC50 = 14.012 mg/l).