The effect of austcnitc and fcrritc phases on fraclurc stirfacc morphology were examined for a duplex stainless steel by focusing on the crack propagation properties closely related to the formation of fracture surface. The materials tested have the austenite phase and the ferrite phase in the proportion of seven parts to three. The forged duplex stainless steels were tested instrumented Charpy test to investigate the ductile fracture toughness and the crack propagation energy. The microstmcturcs beneath the fracture surface were investigated to reveal the relationship between microstructures and fracture surface morphology. As a result of observations, it was found that the fracture surface profiles examined on austenite grains showed rough periphery and became fine, whereas the fracture surface on lerritc grains was relatively flat. It is caused that the crystal orientation of the austcnitc phase was random and the cracks on the austcnitc grains spread in various, while the ferrite phase have (001) texture and on the ferrite grains spread only in one direction.