Abstract: In order to study the corrosion property of a kind of domestic continuous basalt fiber BF-CSH-01, the mass loss, monofilament strength, tensile properties of tows and flexural strength of the composites were investigated in different immersion periods of sodium hydroxide and hydrochloric acid of 2mol/L at 80℃. The results indicate that the acid resistance of this basalt fiber is better than the alkali resistance, which is contrary to BF-CMD-01 basalt fiber studied before. The tensile strength of BF-CSH-01 monofilament declines synchronously with the mass in acid mediums, while the tensile strength declines intensively with the little mass change in alkali mediums. The acid and alkali have a great effect on the tensile strength of the tows and on the flexural strength of its reinforced composites. The regularity of strength is in conformity to monofilament while the modulus is insensitive.