Based on the MFRSR(multi-filter rotating shadow-band radiometer)data observed at Taihu Site during May 16,2008 to April 17,2009,the aerosol optical depth (AOD) is retrieved and its statistical results at 415 nm,500 nm,615 nm,675 nm and 870 nm are given,as well as the statistical results of turbidity coefficient and Angstrom wavelength exponent.Results indicate that the maximum value of AOD at these five wavelengths are 1.9,1.6,1.3 and 1.2,respectively;The half width of spectrum distribution are 0.90,0.70,0.55,0.45 and 0.25,respectively;The AOD value at its frequency distribution peak are 0.750,0.550,0.475,0.425 and 0.425,respectively.The AOD value is largest in spring,smaller in summer,and smallest in winter at all these five wavelengths.The Angstrom turbidity coefficients range from 0 to 1.25,with 60% data larger than 0.4 and 97% data lager than 0.2;The Angstrom wavelength exponent in spring,summer,autumn and winter are 0 to 3.0,0 to 2.8,0.2 to 2.0,and 0.2 to 2.0,respectively.It reflects that atmosphere is polluted occasionally and influenced remarkable by anthropogenic sources.Considering the peak distribution of wavelength exponent,it is suggested that there are larger particles existing in spring and summer than in autumn and winter.