Low affinity and poor color fastness are confronted when dyeing silk fabrics with mulberry dye.For fully displaying the color feature of mulberry dyes,proper dyeing parameters and mordant dyeing processes were selected to dye silk fabrics.The stability of natural dye mulberry sorosis and its mordant dyeing effects on silk fabrics were investigated by testing the visible absorption spectra of mulberry sorosis dye solutions,color depth(K/S value) and color fastness of the dyed silk fabrics.The results indicated that natural dye mulberry sorosis solution showed satisfactory color feature at pH of 4 and 80 ℃.Mordant dyeing,especially post-mordanting dyeing process,can greatly improve the performances on both color depth and color fastness of the silk fabrics dyed with natural dye mulberry sorosis.