The variation degree after mineralization period is important for the Datangpo-type manganese deposit's exploration and prediction.However,current studies seldom involve the analysis and evaluation of this kind of variation.Some papers exhibit related researches but only focus on the analysis of the phenomenon in some deposits,lacking quantitative evaluations and analyses and studies of the correlation between characteristics of deposits and variation degrees after the mineralization period.To make up the defect of previous studies,this manuscript takes the Minle manganese deposit,which is the typical Datangpo-type manganese deposit in northwestern Hunan,as an example,firstly analyzing possible variations of Minle manganese deposits during and after mineralization and selecting influencing factors according to the various geological features of the Huayuan district,secondly using the Analytic Hierarchy Process model to calculate the weight of factors,finally calculating the index of variation degrees after the mineralization period of the Minle mining area according to results of the score of weightsand combing it with thicknesses and shapes of ore bodies to analyze the relationship between the variation degree after the mineralization period and the preservation of manganese inside the Minle mining area. The study provides a new thought for quantitative evaluation of Datangpo- type manganese deposits.Methods:Choosing proper influencing factors according to previous papers and the data of wells and field works. Using the AHP (Analytic Hierarchy Process) method to calculate the weight of each factor.Analyzing the relationship between manganese ore-bodies' shape and thickness and the variation degree after the mineralization period according to ratios respectively of the area with low variation degree in areas of ore- bodies' various thicknesses (10m, 7m, 4m, and 1m), amounts of wells with low variation degrees in amounts of wells of ore-bodies' shapes (compact and massive ores and banded ores),and amounts of wells with low variation degrees in the total amount of wells,which is calculated by the GIS spatial analysis function.Results: The Minle manganese deposit's variation degree after the mineralization period can be divided into two levels according the changing of its coefficient. The coefficient which is bigger than 3.9274 means the strong variation after the mineralization while the coefficient which is smaller than 3.9274 represents the weak variation.The mean and median of variation degree coefficient are respectively 3.8887 and 3.9275,which means the variation degree of Minle mining area is not strong.The amount of wells,the amount of wells develop compact and massive ores and the amount of wells develop banded ores of the weak degree district occupies respectively 64.1%,64.8% and 63.2% of their total amounts of wells. The size ratio of areas with weak variation in the area of which the thickness is over 10m is 97% while the same ratio in the area of which the thickness is over 1m drops to 70%.Conclusions: The developing degree of faults weights the most in producing impacts on the variation degree after the mineralization period, the uplifting degree of stratums weights a little lower and the thickness of manganese-bearing rocks produces less impacts.For the Minle mining area,the variation is strong in two sides and weak in the middle.The western side is mainly influenced by the uplifting of stratums and the eastern side is mainly influenced by faults. The Minle manganese basin has the tendency that the variation degree after the mineralization period is higher and higher from the center to the edge and the area with weak variation is easier to find the manganese deposit.