Abstract: Water resources carrying capacity(WRCC)is an important rigid constraint to achieve 'spatial balance',and its scientific evaluation is of great importance for the construction of regional ecological civilization and sustainable development.Due to the effects of many factors, the evaluation of WRCC generally has some uncertainties, however, such uncertainty was not quantified in most of previous studies.Taking Xinjiang region as the study area, this study mainly focused on quantifying the uncertainty of WRCC evaluation caused by indicator weights and data.Bootstrap sampling, random sampling of uniform distribution hypothesis, random error generation methods were used in generating indicator weight samples and data samples.The concepts of membership degree and uncertainty degree were proposed to quantify the uncertainty in WRCC evaluation.The results showed that based on Bootstrap sampling and uniform distribution hypothesis, the uncertainty degrees of WRCC evaluation caused by the uncertain indicator weights were 21% and 17% in the study area, and that caused by the uncertain data was 8%.With the increases of uncertainty in weights and data, the uncertainty degrees of WRCC evaluation caused by them also increased.Furthermore, the data uncertainty had a greater impact on WRCC evaluation, according to the method of increasing the equal amplitude error.The research results can provide reference for regional economic development and sustainable utilization of water resources.