[Objective] Oasis stability in Pishan County of Xinjiang Wei Autonomous Region was evaluated in terms of the balance between supply and demand of water resources under the condition of water resource constraint in order to provide scientific basis for the protection of local ecological environment and associated decision making in this region.[Methods] Data of land use types in Pishan oasis from 1998 to 2012 were elicited from Landsat TM/ETM⁺ remote sensing images and other basic geographic data based on RS technology. Combined with the hydrological and meteorological data(temperature, precipitation data), comprehensive water demand of social economy and natural ecological system in Pishan oasis were estimated. Upon these, the balance between supply and demand of water resources and oasis stability were preliminary discussed.[Results] The canal system utilization coefficient of Pishan oasis was estimated at low level, farmland irrigation quota and arable land water consumption proportion were high, also the social and economic water consumption were increasing. The water demand had increased 2.73×10⁸ m³ in recent 15 years, and there were big insufficiency on the supply of status quo. The total water deficit reached 2.74×10⁸ m³ in 2010. In 2012, it was eased, but the yearly water deficits of natural ecological environment were at an overall increasing tendency. Deficit of natural environment accounted for 59.75% of the total water deficit, and it had great imbalance between supply and demand.[Conclusion] According to the present oasis area, a big gap in supply of water resources existed, the oasis was in an unstable state.