To keep ‘sustainability’ becomes important in urban planning because of ecological condition. But concerning declining fertility, keeping fertility is the biggest problem. In this sense, to keep a community sustainable, preparing convenient living condition is necessary according to researches of anthropoid's behavior. In this paper, a concept called ‘regional system’ will be introduced, which means that whole community items such as parks, roads, houses, hospitals, shops, day nurseries and people who lives are linked and supported each other. It is assumed that to stop declining fertility, preparing a convenient regional system for child rearing people. Firstly the paper has examined that conditions of parks, roads, public traffics and housing etc. are key issue of convenient regional system by questionnaires to child rearing parents and nurses. Secondly the paper proposes a new method of participation. The key of this method is that needs for how to link parks and houses or how to link day nurseries and shops are included. In this method, needs of child rearing people are once accepted as a comprehensive plan for child rearing people to encourage their participation. And then it is used as data to make plans of local government. This paper proved this method is effective to make plans for realize convenient regional system. Lastly, according to the results of investigation, this paper shows problems of local government in the sense of realize the method using comprehensive plan for child rearing people.