<p> Low birth weight infants are increasing in Japan at present and even though medical standards have been improving, the number of disabled children requiring medical care is increasing. However, there has been no studies concerning the improvement of living environment for the disabled children in the process of growth and development. Severely disabled children require significant assistance in daily living activities. The burden of the caregiver is particularly large for excretion assistance. In order for disabled children to acquire excretion activity, it is important to create an environment in association with the growth and development of disabled children.</p><p> Therefore, in this paper, we investigated the changes in mental and physical functions and actual situations of excretion in association with their growth and development and the change in excretion environment. As a result, it was found that some disabled children were improved in the expression of the desire to urinate and defecate and the excretion places for some others were changed.</p><p> First of all, we visualized the growth and development of disabled children, and clarified the state of change in excretion environment by each visualized pattern. As a result, the states of change could be classified into five patterns; three patterns with change and two patterns without change. The disabled children whose toilet tools were changed corresponding to their pattern could excrete in the toilet. Meanwhile there were the cases where environmental improvement was physically impossible. Excretion environmental improvement already had been made in one of the two patterns without change and it has been made possible for them to continue their excretion activity. In another pattern, requiring medical care was needed and excretion on the bed had been established.</p><p> From the above, reached the following conclusions:</p><p> </p><p> ・Many improvements of the excretion environment associated with growth and development are due to change of tools.</p><p> ・The cases where excretion environment has been appropriately improved associated with disabled children’s growth and development, encouraged disabled children’s development.</p><p> ・In order to make them continue excretion activity in toilet, the improvement of living environment is important.</p><p> ・If they can be in a sitting position, some disabled children can excrete at home if excretion environment is improved.</p><p> ・Difference in the way of thinking of main caregiver about excretion, their economic situation and the lack of information concerning environmental improvement make the improvement of excretion environment difficult.</p>