Autism is defined as A mental condition, present from early childhood, characterized by difficulty in communicating and forming relationships with other people and in using language and abstract concepts. today in most of the children are suffering from this problem. The developing process of the child usually 18 months, The same person with autism also does the same. The average time for the child to pronounce the word is one and a half years. Some people may also take three to four years to speak. if the child does not speak within 18 then we should check up that baby, it may be autism. if we call them but he cannot able to respond then we should check up that baby too. so there is no exact reason what is the cause of autism. but some doctor says that the cause of the autism is heredity. Similarly, due to some chemicals, there is also an investigation on whether there is a problem of autism. Even if there is a problem with the pregnancy, behavior, work, or such a situation, there may be autism in the child.