以宁夏中部干旱带为研究区，利用区域内的国家标准气象站1954-2016年4月-10月的日降水资料，运用Morlet小波分析、Mann-Kendall法及气候趋势系数等方法分析了宁夏中部农作物生育期内有效降水量（Pa）的时空变化特征及其未来趋势。结果表明：Pa自北向南依次增大，区域多年平均216mm，占总降水量的75.25%，其中8月份最大为55.9mm，7-9月占总有效降水量的70.8%。60年代为丰水期，正累积距平为238.7mm，70年代进入枯水期，负累积距平226.1mm，2010年以来则有所增加；Pa存在3a和6a及10a主周期；各地未来有效降水量均呈减少趋势，变幅为2.2-5.2mm/10a，全区Pa降幅3.5 mm/10a。4-10月份区域内的总降水也呈显著减少趋势（P=0.05）降幅为5.3mm/10a，其中盐池降水减幅最小0.8mm /10a，海原减幅最大8.8mm/10a。

The arid zone in the middle part of Ningxia is focused on as the research area by using the Morlet wavelet analysis，Mann－Kendall method and climate trend coefficient method，the characteristics of precipitation on the multiple－time scale change and variability tendency and gradient of effective precipitation ( Pa ) in the growing season are analyzed by the daily precipitation data of the national standard weather station in the research area during 1954－2016． Ｒesults indicate that Pa increases from north to south in the middle part of Ningxia，with an average annual of 216 mm，accounting for 75．25% of the total precipitation，of which the maximum is 55．9 mm in August，and 70．8% of the total effective use of precipitation between July and September． In the 1960s，during the abundant period，the positive anomaly was 238．7 mm． In the 1970s，it entered the dry period，and the negative cumulative anomaly was 226．1mm． Since 2010，it has increased． Pa has 3，6 and 10 a main cycles． The effective precipitation in all regions showed a decreasing trend，the amplitude was 2．2～ 5．2 mm/( 10 a) ，and the Pa in the whole area was 3．5 mm/( 10a) ． The total precipitation in the region from April to October also showed a significant decreasing trend ( P= 0．05) ，which was 5．3 mm/( 10 a) ． Among them，the decreasing rate of precipitation in Yanchi is the smallest by 0．8mm/( 10a) ，and the largest decrease in Haiyuan is 8．8 mm/( 10 a) ．