Quercetin is polyphenol flavonoid and exhibits anti-inflammatory, antihepatotoxic antihepatotoxic, antiulcer, antiallergic, antidiabetic, antiviral and antioxidant activity. It is found in many herbal plants such as in Cocculus hirsutus. The aim of this research work is to develop a simple, accurate, precise and economic UV spectroscopic method for the determination of quercetin. The estimation of quercetin by spectroscopic with maximum absorption at λmax 256.30 nm using developed solvent [n-butanol : water : acetic acid (7:1:1)]. Beer-Lambert’s law is obeyed in the concentration range of 0-12μg/ml and is described by the regression equation y = 0.063x + 0.005 with a regression coefficient (r2) = 0.999 (n = 5). For Quercetin, the value of molar absorptivity and Sandell’s sensitivity are 6.3197 x102 L/mol/cm and0.4782 μg/cm2, respectively and of LOD and LOQ are found to be 0.4486 and 1.3595μg/ml, respectively. The percentage recovery of quercetin was found to be 98.66 %. The % RSD for intraday and interday precision was 1.27 and 1.40 respectively showed excellent % RSD which is less than 2. The developed method was validated in terms accuracy, precision, linearity and robustness. The statistically validated results indicate that the proposed method has good sensitivity, accuracy and precision. The method is simple and economic as compare to chromatographic methods. The developed method was successfully applied for the determination of Quercetin in herbal plants and its product.