A method of inhibiting the formation of dental plaque comprises staying an oral cavity cleaning composition in oral cavity for at least 30 seconds, 5 times a day, for a total period of 2 weeks, wherein, the oral cavity cleaning composition, comprising 35˜50 parts by weight of tea leaves extract, 10˜25 parts by weight of Stevia leaf extract, 10˜25 parts by weight of lemon extract, 10˜15 parts by weight of mint leaf extract, 10˜20 parts by weight of Lonicerae Flos extract, 20˜30 parts by weight of kuding tea leaf extract, 5˜10 parts by weight of xylitol and 25˜35 parts by weight of ethanol.All ingredients in the composition are obtained from edible plants that are very effective in oral cavity care. Furthermore, the composition is non-irritant to the body and can be used for long term.