A new type of interpenetrating polymer network based on a liquid crystal line polymer : a semi-interpenetrating liquid crystalline polymer network comprising the liquid crystalline polymer (LCP) PET/60PHB and crosslinked polyacrylonitrile (PAN) (for short : semi-ILCPN LCP/PAN) was successfully prepared. The compatibility and thermal properties of the semi-ILCPNs with different amounts of the crosslinking agent were investigated by FTIR, SEM, DSC, and TGA.