Ground motion simulation can provide reference for buildings seismic design in areas lacking earthquake records. High frequency attenuating factor （κ） is an important parameter in ground motion simulation， controlling the drop of Fourier spectrum shape in the high frequency interval. Luring magnitude 6.8 earthquake records within 150 km of the epicenter are selected to devel op κ. Parzen window is used to smooth the cluttered Fourier amplitude spectrums （FAS）. The frequency interval in FAS with the smallest pH function is selected to fit the κ. The approach improves accuracy of identifying lowest and upper frequency， and the sta bility of the calculation. κ are calculated based on 20 stations of horizontal records and the distribution trend of κ is analyzed. The re sults show that FAS is gradually smooth with the increase of the window width， and it is significantly different from the original spectrum when the window width is larger than 1 Hz. Compared with 12 window widths， the window width of 0.4 Hz is the best. The window of 0.4 Hz width makes the curve smooth and the error of κ small. There is a significant directional difference in κ distri bution. κ in EW direction increases with respect to epicenter distance， and κ in NS direction decreases with respect to PGA.