In this paper,we studied on the properties of resistance to acid of aramid,continuous basalt and glass fibers.The mechanical properties and loss rate of mass of three fibers were discussed after different times treatment at 65 ℃,80 ℃ and 95 ℃ temperatures and 2 mol/L hydrochloric acid.The results show that the properties resistance in acid of aramid fiber is the best among three fibers.The maintenance rate of breaking strength and elongation of aramid fiber is the best,the continuous basalt fibers is the second and the glass fiber is the worst.So,the aramid fiber is more suitable to use in the acid environment and the continuous basalt and glass fibers should be avoided for use in acid environment.