In the present study Cissus quadrangularis L extract was prepared in two different solvents depending on polarity and was tested for the presence of different phytoconstituents. Phytochemical analysis of Cissus quadrangularis L revealed the presence of alkaloids, saponins, flavonoids, triterpenes, tannins and steroids. Cissus quadrangularis L has rich presence of phenols and flavanoids. Antioxidant, antiviral, antifungal, diuretic, laxative, anti-diarrhoeal activities are reported in Cissus quadrangularis L. The phenols are the centrally active class of phytoconstituents which are responsible for many pharmacological activities. Acute toxicity study was carried out on the total phenols extract of Cissus quadrangularis L (HECQ). The estimated LD50 of HECQ was 290.00 mg/kg indicating its moderately toxic properties. This study not only substantiate central depressant and muscle relaxant activity of Cissus quadrangularis L, it also attempts to establish phytopharmacological co-relation with presence of phenols are known for their central effect. Ethnobotanically similar Vitaceae plant contains triterpenes and phytosterol like ?amyrin, 24-metaylene cycloartenol and ?-sitosterol has reported sedative, antianxiety and anti-depressant activity. Further studies are suggested to explore mechanism of action of Cissus quadrangularis L phenols in concern to interaction with central receptors1