The importance of failure in the daily life . of individual and personality development are recognized by many students and investigators. The experimental study of the effects of failure on subsequent activity is, however, extremely meager. Therefore, the present study is an attempt to know how children behave in the failure situations. It is, further, the purpose of the investigation to determine whether 'children who show undesirable responses in the face of failure may be made, and to modify the children's behavior by the special experiences. The numbers of the subjects of the experiment were about ninty children between the age of 7years-3months and 10years-3months, including equal number of both sexes. In step 1, all subjects were given a failure experience, and the subjects responses were observed by the examiner through a one-side screen and recorded. On the basis of the results, the subjects were classified into three same quality groups; success group, failure group, and control group. In step 2, these 'groups were given each differential experiences. And in step 3, all subjects of all groups were observed again how they respond such a failure situations as in step 1.