The synergetic effect of a reactive compatibilizer and organo-montmorillonite (OMMT) on phase morphology and properties of polyamide 6 (PA6)/polydimethylsilicone (PDMS) blend with a high viscosity ratio of dispersed phase and matrix was studied. A small amount of an amine-terminated copolymer of polyether amine (PEA) and PDMS (PDMS-b-PEA) as a reactive compatibilizer can significantly decrease the dispersed phase domain size. However, the dispersed phase domain size has still been above 2 mu m even when the PDMS-b-PEA concentration reaches 5 wt %. OMMT as the second additive can further dramatically decrease the dispersed phase domain size due to the barrier effect for effectively preventing the coalescence of the dispersed phase domain. Moreover, the presence of PDMS-b-PEA can promote the uniform dispersion of OMMT. The synergetic effect of PDMS-b-PEA and OMMT can also improve tensile properties and decrease water absorption.