To produce liquid crystal polyester fiber capable of providing nonwoven fabric having high porosity, small anisotropy in breaking length and excellent air permeability and flexibility by forming fiber made of a specific thermoplastic resin composition through melt spinning and then removing the thermoplastic resin through dissolving it in its solvent.

This liquid crystal polyester fiber is produced by extruding a thermoplastic resin composition comprising (A) 70.0-90.0 wt.% thermoplastic resin such as polycarbonate and poly(2,6-dimethylphenylene ether) and (B) 30.0-10.0 wt.% liquid crystal polyester such as a liquid crystal polyester including ≥30 mol% repeating structural unit of the formula in a molten state from nozzles so as to form a continuous phase from the component A and a dispersed phase from the component B, by drawing filaments at ≥3 times draft ratio, by cooling them to solidify and then dissolving the component A in a solvent such as chloroform to be removed. The above composition is pref. melted at a temperature higher than the flow-initiating temperature of the component B.