From last few decades there is an advanced use of herbal medicines all over the universe and now there is potential need to study natural drugs on scientific basis to develop their individual monographs. Thuja orientalis
commonly known as arbor vitae or white cedar or morpankhi belonging to family Cupressaceae is well known medicinal plant. Thuja is used for treatment of bronchial asthma, enuresis, cystitis, psoriasis, uterine carcinomas, amenorrhea, rheumatism, skin infections, bacterial dysentery, arthritic pains and premature blandness. The present studies were designed to estimate total phenols and flavonoids content in Thuja orientalis
aerial parts because there are lack of literature investigation regarding this plant. The hydroalcoholic extracts of Thuja orientalis
aerial parts collected from different regions were prepared separately as per standard procedure. Further, the hydroalcoholic extracts were secreened for presence of bioactive phytoconstituents using general chemical tests. The estimation of total phenols and flavonoids content were carried out using standard procedures named Folin Ciocalteu’s assay and aluminium chloride assay respectively. The total phenols content of Tamil Nadu, Rajasthan and Himachal Pradesh varieties Thuja orientalis
aerial parts were found to be 9.12, 8.91 and 8.45% w/w respectively, whereas the total flavonoids content of Tamil Nadu, Rajasthan and Himachal Pradesh varieties Thuja orientalis
aerial parts were found to be 4.21, 3.56 and 3.20% w/w respectively. So, it can be concluded that, Tamil Nadu variety of Thuja orientalis
aerial parts contained higher content of total phenols and flavonoids than Rajasthan and Himachal Pradesh.