SiC f -SiBC composites were produced using NLM 202 and Hi-Nicalon SiC f fibers. Tensile creep tests were performed under a reduced pressure of argon. These composites show a good creep resistance at 1473 K with a strain rate ranging from 10 À9 to 10 À7 s À1 , depending on the stress level. The creep strength was improved by using Hi-Nicalon instead of NLM 202 SiC f fibers, to the extent of increasing the loadability by 50 MPa at the same operating temperature or increasing the temperature by 50 K for the same load. The damage observed in SEM micrographs and the use of the damage mechanics provide evidence that creep is governed by a damage-creep mechanism in two steps.