The fracture behaviors of a newly developed iron-powder reinforced carbon/epoxy laminated composite are investigated in this paper. Three kinds of DCB (double cantilever beam) specimens (without iron powder, with iron powder and with iron powder in a magnetic field) were prepared by the ASTM D 5528-94a. For the third DCB specimen, the unidirectional laminas were stacked with iron powder spread evenly on each lamina’s surface. This process was performed in a magnetic field to keep the iron powder standing along the out-plane direction. From the test data of Instron 5567, the fracture toughness, GI, was calculated by using the compliance calibration method for each of the three kinds of specimens. The calculated fracture toughness shows that the iron powder effectively disturbs the progress of fiber branching between the laminates and provides a good stitching to the in-plane laminates during the fracture.