The morphologies, mechanical properties and thermal stability of bisphenol A epoxy resin/4, 4'-diamiodiphenysulphone(DDS)/liquid crystalline polymer(LCPU) blends were studied. The LCPU content was varied within 0 wt% similar to 15 wt%. The cured materials were characterized by mechanical property test including impact strength, tensile strength, bending strength, elastic modulus and elongation. The thermal stability, largely based on the decomposition temperature (T-d) was investigated by the measurement of thermogravimetric analysis. SEM were used to study the morphology of the blends and the fracture surface of the cured materials. Compared with the unmodified system, the result showed that impact strength was enhanced to 3.6 times and bending strength was enhanced to 20% for LCPU content of 5%, tensile strength was enhanced to 1.5 times for LCPU content of 10%, elastic modulus was improved for 35% and elongation percentage was improved for 1.6 times for LCPU content of 7.5%, glass transition temperature(T-g) was increased 60degreesC for LCPU content of 5% and the decomposition temperature (T-d) was increased 36degreesC for LCPU content of 10%. SEM observation of the fracture surface of the impact specimen showed that the toughened fracture characters were obviously appeared for the blends.