A new thermotropic liquid crystalline polymer (TLCP) with ethoxy side group was synthesized for the preparation of in-situ composite, and the blends of TLCP with poly(ethylene 2,6-naphthalate) (PEN) were prepared by solution blending. TLCP, PEN and blends (2, 5, 10 and 20 wt%) were characterized in terms of their thermal, mechanical and morphological properties. TLCP in the melt showed the nematic phase. The glass transition temperature (Tg) of PEN in the blends decreased with increasing content of TLCP; TLCP acted as a nucleating agent for the matrix polymer. The crystallization temperature (Tc) of PEN in the blends increased with increasing content of TLCP. In the blends, liquid crystalline phase did not reveal any significant macrophase separation and thermal degradation at the processing temperature. From scanning electron micrographs of cryogenically fractured surfaces, the TLCP domains were found to be fine and uniformly dispersed having 0.2 to 0.3 μm in size. Interfacial adhesion between TLCP and the matrix polymer was determined to be good. The modulus of TLCP/PEN blends were enhanced as TLCP's content increased.