Paddy is the important crop to be grown in Taiwan. There are two paddy may be grown in a year, wherever irrigation water is available. It maintains the self-sufficiency in food-crop products so as to ensure the security of food supplies and raises farmers income in Taiwan for a long time. This paper is to introduce the aspects dealing with irrigation performance and management prevailed in Taiwan. Due to the recent socio-economic changes, the water demand has been increasing with the expansion of industrialization and urbanization. The acquisition of new water supplies for agricultural irrigation has become more difficult and costly. Besides, the existing irrigation water sources face the pressure of competition use of other purposes. Irrigation encompasses social, economic, policy and institutional aspects, such as irrigation science, ecological function, entry into WTO challenges, etc. As a result, a great effort to ensure efficient utilization and sustainable use of irrigation water through improvement in irrigation system and water management is being made and also discussed in this paper.