The present experimental study was conducted to investigate the explosive spalling behaviour of ultra-high strength concrete (UHSC) including 15 concrete specimens with cubic compressive strength of 115~134 MPa subject to ISO834 fire. The effect of water-binder ratio (W/B), porosity, fibre type, fibre dosage, size of specimens on the high temperature spalling was investigated. Test results show that the UHSC with 0.15 W/B has lower porosity and higher strength than that with 0.18 W/B and more likely to undergo spalling; the addition of 0.5% short steel fibre in volume, which was intended for improving the ductility of concrete at room temperature, cannot prevent spalling when the concrete specimens are subject to fire; the addition of 0.15% polypropylene fibre (PP) in volume can prevent spalling in both ?100mm × 200mm specimens and ?300mm × 300mm specimens. No spalling is observed when 120 MPa UHSC with 0.15 water-to-binder ratio encased steel columns with 0.5% short steel fibre in volume and 0.15% PP fibre in volume are subject to loadings in fire condition. The fire tests reveal that the UHSC with hybrid fibre in the present study can prevent spalling even under axial load up to ultimate compressive strength subject to fire.