Abstract: Based on the meteorological data of 16 stations in Weihe river basin during recent 55 years (1954-2008),and using the methods of linear regression,Mann Kendall test,Pettitt test and Morlet wavelet analysis,the variation characteristics of tendency,mutability and periodicity for the annual and seasonal mean temperature were analyzed.The results showed,(1)in the 95% confidence interval,the annual and seasonal mean temperature presented significant rising trends,and the temperature rose highest in winter.(2)There was an irregular spatial distribution of annual mean temperature,which showed a decreasing trend from the centre near the Xi'an station to all directions.(3)The annual and seasonal mean temperature had significant abrupt changes and 1993 was a watershed year for the river basin.(4)The annual mean temperature existed multiple time scale features,with the principal periods of about 3,7,23 and 55 years，and the phase change of 55 years period was the most obvious.Except in summer,the time scale features of mean temperature in other seasons were roughly consistent with those in annual.The research results provide reference for analysis and predictions of the climate change in Weihe river basin.

Key words: Mann Kendall test, Pettitt, Morlet wavelet analysis, Temperature, Weihe river basin