Six infrared absorption bands caused by Jwater in phosphate glasses were identified. The relationship between the absorption coefficient at 3.47m due to water and fluorescence lifetime of Nd3+ weve determined. The variation of water contents during melting was measured in detail and the result showed that it increased obviously after stopping dry gas bubbling. The BAP has been used to remove the water in phosphate laser glass and it is easy to fabricate a glass with K3.47μmOH=1.