Broad infrared emissions at 1131, 1107 and 1291 nm were observed in the bismuth doped aluminosilicate glasses under 532, 690 and 808 nm excitation respectively. The origin of the broadband infrared luminescence was investigated in the aluminosilicate glasses. Based on the energy matching conditions, it is suggested that the infrared luminescence centres might be Bi 1z ions and BiO molecules. The broadband infrared luminescent characteristics of the glasses indicate that they are promising for broadband optical fibre amplifiers and tunable lasers.