A single fiber Ti/SiCf composite specimen was loaded incrementally and unloaded in-situ on a beam line at the European Synchrotron Research Facility (ESRF) in Grenoble. It was possible to measure the strain along the fiber with a high spatial resoln. (50 mm) within the titanium matrix. The interfacial frictional shear strength inferred from the longitudinal strain profile of the broken fiber was calcd. to be around 200 MPa. The result is compared to the interfacial shear stress derived from other methods developed to evaluate the matrix/reinforcement interface in this system. An axisym. finite element model gave good agreement between the numerical and exptl. results. [on SciFinder (R)]