Cornsilk refers to stigmas of female maize flowers. Corn silk contains abundant flavonoids. Flavonoids show a variety of biological activities, such as antioxidants. Several methods, such as microwave, ultrasonic, supercritical fluid extraction, and multiple extraction technologies, were used to extract flavonoids from corn silk. The ultrasonic-assisted extraction method (UAE) seems to be very reliable among these methods. UAE has the advantage of simplicity and can be easily implemented with other extraction techniques. Hence, the current study aimed to determine the effect of the ratio (material: methanol) and concentration of methanol corn silk extracts in UAE. The experimental design used was a factorial Randomized Completely Block Design (RCBD) with two factors and three replications for each treatment. The two treatments were: A1=methanol (1:4) (w/v), A2=methanol (1:6) (w/v), A3=methanol (1:8) (w/v) and methanol concentration (60, 70 and 80%). Results showed that the ratio of methanol and concentration had a significant effect (p<0.05) on nutritional and phytochemical content in corn silk extracts. The best treatment interaction on A3B3 (1:8 (w/v) and methanol concentration 80% with nutritional content analysis (water 6.38%, ash 1.11%, fat 0.44%, protein 4.70%, carbohydrates 87.23%, and dietary fiber 2.72% and the analysis of phytochemicals content (total phenol 2.91 µg GAE/g, flavonoids 2.32 µg GAE/g, beta carotene 1.07 ppm, vitamins C 12.47 mg, and antioxidant activity 27.08%). The implication of this study is that corn silk extracts could be developed as a source of nutrients and bioactive compounds, and corn silk waste can be converted into value-added products.