The invention discloses children toothpaste for preventing decayed teeth. The toothpaste is prepared from the following raw materials in percentage by weight: 25-35 percent of abrasive, 15-20 percent of humectant, 0.5-3 percent of a blocking agent, 1-3 percent of a foaming agent, 46-52 percent of a traditional Chinese medicine preventive, 1-2 percent of a sweetening agent, 0.7-1.2 percent of an auxiliary and the balance of pure water, wherein the traditional Chinese medicine preventive is prepared from the following components in parts by weight: 4-6 parts of salvia miltiorrhiza extract, 7-9 parts of dried radix rehmanniae extract, 5-7 parts of radix ophiopogonis extract, 2-4 parts of radix paeoniae alba extract, 1-3 parts of rheum officinale extract, 5-7 parts of bitter gourd extract, 9-11 parts of sarcandra glabra extract, 5-7 parts of pseudo-ginseng extract, 7-9 parts of wormwood extract, 9-11 parts of bletilla striata extract and 3-5 parts of licorice root extract. The toothpaste has the effects of clearing heat, eliminating internal fire and sterilizing, and is capable of effectively preventing occurrence of decayed teeth, eliminating foreign odor from oral cavity and maintaining the oral cavity to be fresh and clean.