The purposes of this study was to investigate the levels of behavioral changes with self-discipline of preschool children who received children as researchers learning and to compare the changes. The sample used in the research was boys and girls, with 3-4 years of age, of first year kindergarten in the first semester of 2011 academic year of Satit Pattana School. One class with 25 students was selected from 5 classes by purposive sampling. The experiments were carried out within the period of 8 weeks, 4 days a week and it took 50 minutes for each one. The instruments used in the study were plans of children as researchers learning and an observation form for the self-discipline of preschool children with the reliability of .80