In this paper, we describe a whole-new, user participatory learning environment in zoo by adopting mobile network devices. It is likely that zoo will be an effective learning environment especially for children if we make good use of resources in zoo. We therefore proposed and operated user-participatory information technology so that even children can learn about animals and nature by using them. Navigation system, an audio and video guidance with ipod, lets children see something that one can't see in one's normal life. Voice Trackback System, a participatory voice message gathering system with mobile phone, helps children to record their messages easily, and to access the voice data on the web freely. By using information systems like these in zoo, visitors including small children learn more about animals and nature in interactive ways.