In this paper, the effect of modified-silicon rubber (MSR) on thermal degradation and anti-droplet properties of melamine cyanurate (MCA) flame retardant polyamide 6 (PA6) composites was studied by using thermogravimetric analysis (TG) and vertical burning test. TG analyses indicated that modified-silicon rubber could markedly promote the condensation process of PA6/MCA/MSR composites compared with PA6/MCA composites, and the char residue of PA6/MCA/MSR composites at 600¡æwas much higher than that of PA6/MCA composites. DTGcurves showed that MSR could slow down the rate of degradation of PA6/MCA composites. More importantly, there was no melt-drip produced when PA6/MCA/MSR composites was burning. It was concluded that MSR increase the thermal stability of composites and could effectively prevent the formation of melt drip.