Abstract: in order to diclose the key scientifi issues relating to resevoir fuid interactions during the production of coalbed nethane, t is necessary to develop anew.special and non-destructve methodoiogy for analyzing coalresevoir properies. This authors.from theoretcal and technical aspects reviewed the curent state ofthe ar in the peroaphysics and fuid properies evaleation of coalbed methane reservoir by using NMR relavation time analysis.Three major achievenents were obtained.Fifrtly several models and methodology were built or quanitatve characterzation of coal porosty.permeabilty pare size distirbution wetabilty and methane isothermal disoption curve of ca . Secondy.the theoreical basics and appications for quantitative identfcation of muiti- hase(bul-coal adsorbed- and porous medium confine -) met ane and mii-phase bul.caiary and adsobed -) moistures in coals were verifed.Lastya quantfied model to evaluate theficiency of water replacement y Co_2 injection was provided. The above achievements can provide certainly supports for the further researches of the potentia interaction mechanisms and multiple geological effects resulting from the interactions of multi- phased gas and water during gas production.