To reveal the causes of the crime in imprisoned criminals for effectively preventing the crime by a classic psychological experiment and analysis of a case from the psychology of an imprisoned criminal,the result show that not only the early exposure in a lack of love leads to emergence of the problen-children but also this problem results from the transmission of the family structural problem and the improper early discipline of the parents leads to the malformed growing of the personality which is repeatedly transmitted.Conclusion is that the key way for the crime prevention is the love which is given to infants in its early years,especially the love of the mother.