The relationship between solar activity and the width of Chinese fir grow th-rings has been analysed on the basis of wavelength.There are two periods,11 years and 6 years,for solar activity,and two periods,9～12 years,and 5～6years,for the width of Chinese fir growth-ringsin Fujian Province.The results of the study indicate a negative correlation between width of Chinese fir growth-rings and solar activity.