A physical retrieval method of total precipitable water (TPW) by GMS-5 satellite infrared-split window channels and MODTRAN radiative transfer model was developed. TPW retrieval tests by using data of summer in 1998 were performed and the verification of retrieved results by using radiosonde data was given, whose RMSE was about 3.30mm. To apply a physical retrieval method operationally, a scheme different from one method above was designed, which was performed through GMS-5 multi-infrared channels’ data and RTTOV7- a fast radiative trasfer model, and whose RMSE was about (4.09mm). The results show that computation cost of the method for RTTOV7 is reduced greatly, which is satisfied for operation purpose.