Baby one and a half years old teeth black, may be exogenous coloring or dental caries, specific need to go to the hospital to check the oral cavity to determine. 1. Exogenous coloring: one and a half years old children’s teeth have basically fully erupted, when the diet with pigmented foods, such as candy or mulberry, the color can be attached to the tooth surface, may cause the whole mouth of the teeth black, black, temporary discoloration. Generally, after cleaning by brushing, the pigment can be removed. 2. Dental caries: when oral cleaning is poor, due to the presence of bacterial food debris, can cause dental caries, tooth defects black, appear after the need to use instruments to clean the decay of the tooth tissue in a timely manner, resin filling, to prevent caries continue to deepen. Normal teeth are milky white or milky yellow, blackened recommended timely examination and treatment in the hospital.