The chacracter of the local Ⅱ grade fly ash from Jiangxi Province was studied using microanalysis technology,and medium strength grade of high fly-ash content concrete(abbreviation : HFCC) was prepared by using five different contents of fly ash and the other local typical raw materials of Jiangxi Province through high-substitute way,then the mechanical properties and durability of the concrete were discussed.The results show that the growth of later strength of HFCC is more substantial than the normal concrete,and its 56 d strength may be over that of the normal concrete,both of the elastic modulus-strength ratio and the permeability are above the normal concrete,but the anti-frost ability and anti-carbonation ability are decreased.