According to the delimitation standard of Meiyu (plum rain) periods defined by Xu Qun, the Meiyu series was prolonged from 2001 to 2005,the parameters include Meiyu duration, Meiyu rainfall, Meiyu cumulative intensity, Meiyu beginning date and Meiyu ending date.The temporal evolution of 121 a annual Meiyu parameters of five stations in the mid-lower reaches of Yangtze River was analysed.The trend variations of Meiyu parameters show that both of the Meiyu duration and the Meiyu rainfall will increase, both of the onset date and the ending date of Meiyu will be in advance in the following 10 a. The periods of four Meiyu parameters are analyzed by Morlet wavelet analysis. It is found for both of the onset and ending dates of Meiyu period there are obviously interannual oscillations, the main periods are 2~3 a and 6 a, the onset date of Meiyu also has a 12 a interdecadal oscillation and the ending date of Meiyu has a 16 a interdecadal oscillation since 1980. The Meiyu duration has 8 a period, the Meiyu rainfall obviously has 4 a and 8 a interannual periods and a 16 a interdecadal period since 1990s.