1.Little language, poor communication, can not maintain a conversation; repeat language, parrot-like language; 2.No response to their names, listening but not listening, sometimes only to their own interest in the instructions have a response; 3.Poor eye contact (such as feeding food will not look at the foster) 4.Smile at him, will not smile in response to you; 5.Gaze can not follow the moving object; 6.Will not use the index finger to indicate When you point to an object, most of the time the eyes do not follow the direction of your finger; 8. 12. does not fit in, does not play with other children, does not share things that interest or amuse him/her; 13. does not ask for help or does not make simple requests; 14. is not interested in toys and games that children usually enjoy; 15. behaves in a stereotypical manner. Parents should pay attention to the following conditions if the infant or toddler appears at the appropriate age: 1. 6 months of age or older, still no laughing or other happy expressions; 2. 9 months of age or older, still no interactive sharing sounds, smiles or other facial expressions; 3. 12 months of age or older, still no yapping; 4. 16 months of age or older, still no words; 5. 18 months of age or older, still no food indicators; 6. 6. 24 months of age and still no two-word meaningful language (not including imitative language); 7.