Purpose : This study is for investigating the factors influencing on treatment effect of devel-opmental disability children under 6-year-old.Methods : This study was investigated March, 2003 from January, 2003 to child fewer than 6 ages and parent each 43 people who is undergoing medical diagnosis from occupational ther-apy of K university hospital, S hospital, C hospital.Results : Obstacle type of 43 disabled children handicap by 50% and language impairment, mental retardation, sight obstacle, difficulties. It is 25.6% that there is no family member that can give help for disabled children’s treatment, is that 1 person is more 69.8%, and that have 3 people 4.7%, and in 25 points full marks that stew of family more than 21 points by 79.1% lazi-ness or family of stew that in general by high thing appear. Disabled children was using aver-age 4.16 places’ treatment institution during a week. Total number of treatment during a week is 5.19 times of treatment per average one child patient. While child’s treatment adaptation degree is that 32.6% well regardless of sentiment or hygienic condition, 37.2% when sentiment or hygienic condition is good well, and 18.6% is usual, 2.3% is different according to sentiment or hygienic condition therapist or treatment institution, and 9.3% is not well in most case. Comparing coefficient of correlation with adaptation degree and cura-tive effect when treat and treatment actual conditions of family’s support, home treatment num-ber of times, medical fee, treatment equipment utilization number of times, treatment number of times etc. and child’s characteristic of child’s age, obstacle grade, duplicated obstacle number and so on, Child’s duplicated obstacle number showed high negative correlation of comparative with curative effect, and child’s obstacle degree showed high negative correlation with curative effect.Conclusion : By result of this study, child’s motor development treatment effect is considered that child’s obstacle degree and duplication number of obstacle is connected. Therefore, it means that efficient and practical treatment to grasp child’s obstacle and state more closely and more interests and efforts of parent and therapist are in need.