【Abstract】The basic function of Argument for “Poverty-of-Stimulus” （APS） is to explain how the children successfully acquire the native language in the situation of the poverty of stimulus. However， if a human being is brought up in isolation， he cannot acquire any language. “Wolf child” is such an example. The paper mainly talks about the author’s understanding of “wolf child” story and the argument for “Poverty-of-Stimulus” from the perspective of language acquisition.
　　【Key words】language acquisition； Argument for “Poverty-of-Stimulus”； “wolf child”
　　1. Introduction
　　In the early twentieth-century， the strong views of Behaviorism and Empiricism stated that the children’s language acquisition was a result of the repeated study and needed stimuli. If the stimulus occurred sufficiently frequently， the response became practiced and therefore automatic （Rod Ellis， 1999）. In contrast to Behaviorist Learning Theory， Innate Theory （1960s， Chomsky） states that the normal children must be born with the ability to acquire a language. These innate language features lie in one part of human brain called language acquisition device （LAD）. According to Chomsky， Argument for “Poverty-of-Stimulus” is the basis of the Innate Theory. Children can gradually acquire a language under the circumstance of “Poverty-of-Stimulus” and the limited language experience.
　　2. “Wolf child” story
　　In 1920， Singh， an American missionary， found two weird children in Indian forest. They looked like wolves and had the habits of wolves. The younger kid died soon after she was rescued. The elder girl was about eight years old， named Kamala by Singh. Although they were brought to the human world， it’s still extremely hard for them to learn and master the new habits and really acquire the human language after several years of training. “Wolf child” story gives us some enlightenment as follows：
　　2.1 In Behaviorist Learning Theory， imitation and positive reinforcement can aid Children to acquire a language. However，， imitation alone cannot possibly account for all language acquisition. Besides， positive reinforcement doesn't seem to speed up the language acquisition process. As for the case mentioned above， “wolf child” was trained several years by imitating the adults around her and repeating the sounds she heard， but she still didn’t successfully acquire the language that was taught to her. And the previous habits of “wolf child” prevented her learning of a new language and human habits.