Abstract: Bulk metallic glasses are regarded as potentialengineering materials because of their unique mechnical and physicalproperties. Mechanical behavior of bulk metallic glass and its compositeover a wide range of strain rates and temperatures attracted manyresearchers' interests. In this paper, a systematic experimental study wereperformed on Gleeble3500 thermal-mechanical testing system to study theeffects of heating rates on mechanical behavior ofZr51Ti5Ni10Cu25Al9 bulk metallic glass underpre-load. The results show that failure models of this material changes fromheating soften to catastrophic rupture with increasing pre-load and heatingrate. Under low pre-load, yield behavior ofZr51Ti5Ni10Cu25Al9 bulk metallic glass iscontrolled by both pre-stress and heating rate; under high pre-load andheating rate the material failures in shear fracture mode and thetemperature of destructive sample is close to or above the glass transitiontemperature when catastrophic rupture occurs, meanwhile the pre-stress ismuch lower than the strength at room temperature and characters of therupture surface are unusual with quasi-static compression experimentalresults. Structure relaxation of amorphous alloy under changing temperatureis discussed and the relations of yield temperature and heating rate as wellas pre-stress are deduced. The reason of catastrophic rupture under thisexperimental condition is also analyzed based on metallographic observationof recovery samples and a critical failure model is also given out.