The play ground of an orangutang in Sapporo Maruyama Zoo was renovated. The design was evaluated by comparison with behaviors of the orangutang and visitors in before and after the renovation. Following results were found: 1) 30 types of the orangutang's “behavioral repertries” appeared by 15 kinds of environmental enrichments. 2) Affiliative behaviors between the orangutang and visitors were encouraged; The orangutang prefers to stay on the concrete flat surface beside the window and the visitors come close to there, their communication through the windows was frequently observed. 3) The observation period of visitors increased 2.5 times as long as before.