An improved conical bubble sonoluminescence U-tube was built. Usingthis setup, the spectra and light pulses of conical bubble luminescence inglycerin were detected. Results show that the spectra are continuum, which arewell fitted by blackbody radiation. The cavitational temperature ranging from 2600 to 3 050 K was calculated from the fitted spectra. The reasons for theexistence of blackbody radiation in conical bubble luminescence were discussedboth from special and temporal sides. The value of radius of cavitational bubbleis about 1.7 cm theoretically, which is greater than that of the bubbleacoustically excited. The width of light pulses of cavitational bubble reached40-60 ms,and this provided enough time for the blackbody radiation. In addition,the light pulses at different wavelength were measured, and results show that thewidth of light pulses increased with the raise of wavelength of spectra, whichproved the mechanism of blackbody radiation. Finally, based on the spectra andlight pulses, the intensity of luminescence was calculated to be about 0.18 J.Intensity