Taraxacum mongolicum Hand-Mazz. has been used as a Chinese traditional medicine for a long history. In this study, its nutritional components were analyzed, including main nutritional components and micronutrients. At the same time, antibacterial test was evaluated. The results showed that nutritional components and mineral elements were very rich. Among of which, moisture, carbohydrate and protein are the major part of nutrients and the content of calcium, potassium, magnesium and phosphorus accounted for over 6.0% of the total minerals. The activity test indicated that only ethanol extracts of T. mongolicum exhibited antibacterial activity against some bacteria, such as Staphylococcus aureus and its isolated strain from air, Escherichia coli and Pseudomonas aeruginosa. The results support the clinical use of the plant in the treatment of inflammation in north China.