Abstract: Methyl methacrylate (MMA) was grafted onto bamboo flour (BF) surface via the method of atom transfer radical polymerization with activators generated by electron transfer (AGET ATRP). The effects on the rheological behavior of BF/polyethylene terephthalate glycol (PETG) composite before and after being grafted by BF were investigated using haake minilab Ⅱ rheometer and rotate rheometer. The capillary rheometer results show that BF/PETG composites display pseudo plastic fluid, and all specimens exhibit shear thinning behavior. Strain scanning results show that compared to that without modification, the stain range of the linear visco-elastic zone of BF/PETG composites with graft modification of BF becomes wider; The frequency scan results indicate that graft modification of BF can accelerate the dispersion of BF into PETG matrix.