This paper analyzes the performance of Tanzanian tourism industry which depends on natural heritage tourism scene particularly natural resources by assessing the trend and forecasting the international tourism demand. The number of international tourist arrivals in Tanzania is used as the proxy measure for international tourism demand. Using the data for the period of 2001q1- 2010q4 and using ARIMA model, the study asserts that the international tourism demand in Tanzania is growing though in a very low pace of about 1% per year. This is less than world average growth that has reported by World Tourism Organization (UNWTO) in 2012 to reach 4-5% per annum. Moreover, the Tanzania international tourism demand is becoming increasingly less competitive and has been fluctuating over the years. Thus to reap enough from the world growing international tourism demand the development of artificial tourism scene to supplement the natural heritage and development of new tourism products should be given more attention in a Tanzania tourism industry development.