A series of novel multi-armed (di-, tri- and tetra-armed) mesogen-jacketed liquid crystal polymers (MJLCPs) were synthesized by atom transfer radical polymerization (ATRP) of (2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene] (MPCS) using di-, tri-and tetrafunctional initiator, respectively. The results show that the number average molecular weight (M-n,M-GPC) was increased versus monomer conversion, and the polydispersities were quite narrow (< 1.19), which is the characteristic of controlled polymerization. The chemical structures of these multi-armed mesogen-jacketed liquid crystal polymers were confirmed by H-1 NMR. The liquid crystalline behavior of these multi-armed MJLCPs with arms ranging from two to four was studied by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide-angle X-ray diffraction (WAXD). It was found that liquid crystalline phases appeared simply when the number molecular weights (M-n,M-GPC) of these multi-armed MJLCPs was higher than a certain critical values, that is, M-n,M-GPC > 1.87 x 10(4) g/mol, 1.84 x 10(4) g/mol, 2.69 x 10(4) and 3.68 x 10(4) g/Mol, which were initiated by coil difunctional initiator, hard difunctional initiator, trifunctional initiator and tetrafunctional initiator, respectively. All the liquid crystalline phase was found to be stable up to the decomposition temperature of these multi-armed MJLCPs. (c) 2005 Wiley Periodicals, Inc.