The task of nature parks is not only to preserve precious nature but to provide us with the places for outdoor recreation. Recently some problems on over use have been reported in such parks in Japan. Though it is necessary for conservation of nature to investigate actual vegetation and to examine appropriate management plan in the parks, it was hardly done in Japanese nature parks. We surveyed actual vegetation and human activities in Mominoki Forest Park in Hiroshima Prefecture as a case study of such a research. It remains few climax vegetation in this park, because it was established in a former stock farm. The main vegetation was secondary forest after cutting down and secondary grasslands at the time of establishment. In 1994,most secondary forests developed. A climax wetland forest, Alnus japonica forest still remains. In addition, there were no vegetational covers in artificial lawns due to overuse. We proposed new management plans of vegetation by the basis of this study.