Synthesis of end-functionalized poly(9,9'-di-n-octylfluorenevinylene)s (EF-PFVs) has been achieved by (i) catalytic olefin metathesis of vinyl groups (chain ends) in once prepared PFVs by acyclic diene metathesis (ADMET) polymerization with 1,2-disubstituted (bifunctional) olefins (DOs) or (ii) one-pot synthesis by combined ADMET polymerization (of 2,7-divinyl-9,9-di-n-octhyl-fluorene, DVF) with end-functionalization/chain transfer using DOs in the presence of ruthenium catalyst, RuCl2(PCy3)(IMesH(2))(CHPh) [Ru(1), Cy = cyclohexyl, IMesH(2) = 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene]. Efficient one-pot synthesis of a series of high molecular weight EF-PFVs has been achieved when DOs were added after a certain period of the ADMET polymerization.