Evaporation is a key element in the hydrologic cycles. It is a very important process in water resources assessment, drought monitoring, hydraulic structure design, hydrologic research and crop production prediction. Since the 1980s, the shortage of water resources in the Yellow River Basin has become more and more serious with the development of local economy and society. The total amount and the spatial distribution of water resources in the Yellow River must be estimated accurately, in which evaporation is an important component, to be estimated. One of the commonly used tools for detecting long-term changes of hydrologic time series is trend analysis method. A number of statistical test methods have been proposed to assess the significance of trends in a time series. In this paper, the Mann - Kendall statistic method and linear trend estimation are used to analyze the long-term trend of evaporation at 58 hydrologic stations in the Yellow River Basin from 1960 to 2001. The results show that the trend of pan evaporation in the Yellow River Basin over the past 40 years almost steadily decreased and the degree of declining is greater than that of rising, especially in April and July. The results of two methods coincide well with each other. In addition, the temporal and spatial distribution of pan evaporation is analyzed briefly in the Yellow River Basin from 1970 to 2001. The results show that the average evaporation in the study area in January over the whole Yellow River Basin decreases gradually from southwestern and northwestern part to middle part and northern part. The spatial distribution of the evaporation in July is similar with mean annual evaporation, both decrease gradually from northeastern part to southwestern part.