The agroclimatic resources possess multple time scales features in time field apart from the apparent spatial variation characteristics,and the large time scales include the small ones.The different time scales conceal different variational rules,such as drought,flood,coldness and warmness etc.The wavelet analysis is a powerful tool because its local variational characte-ristics in time field can reveal the fine structure and the diverse rules containing in different time scales of climate series.Thus,the wavelet analysis method offers a new approach for analyzing the time scale structures and changing mechanism of agroclimatic resources.As an example,the multiple time scales characteristics and variational rules of agroclimatic resources for wheat and maize growth phases in Zhengzhou city were analyzed by means of Morlet wavelet transformation.The results showed that 1)the multiple time scales rules and changing charac-teristics of sunshine,temperature and precipitation series were different on interannual and interdecadal basis.The time variance of precipitation spectrum is the strongest and the most changeful,the temperature spectrum is next and the sunshine spectrum is the last.It is coincident with the fact that the variation of precipitation data is more intense than the ones of temperature and sunshine data.2)A concise and compact information of periodic components of the measurements in the scale-time domain was revealed by wavelet analysis.The results can be proved by other analysis schemes,such as power spectrum,trend analysis,M-K check,etc.3)A clear decreasing trend can be found in the sunshine series over wheat and maize growth period,but the temperature trend is inverse and no obvious trend in precipitation series.Comparing with the trend of global climate change,the consistent and the special local features of climate change existed in Zhengzhou city.