PURPOSE:To obtain a composition having excellent heat resistance, moldability, fluidity, high mechanical strength, especially weld strength and excellent mechanical anisotropic by blending a liquid crystal polyester comprising specific structural units with a specific amount of glass fibers of different diameter structure. CONSTITUTION:(A) 99-20wt.%, preferably 95-30wt.% anisotropic melt phase- forming liquid crystal polyester comprising structural units shown by formula I, formula II and formula IV or formula I, formula II, formula III and formula IV (R1 is group shown by formula V, etc.; R2 is group shown by formula VI, etc.; X is chlorine or H; group shown by formula IV is in an equimolar amount with groups shown by formula II and formula III, having