A novel helical poly(phenyl isocyanide) bearing Boc protectedl-proline pendants (poly-1(m)) was designed and synthesized. Removed the protecting Boc groups on thel-proline pendants led to the formation of helical polymer poly-2(m), which showed high optical activity owing to the preferred right-handed helix of polyisocyanide main chain. Optically active helical poly-2(m)showed excellent catalytic ability on asymmetric aldol reaction. Helical polymer catalysts exhibited enhanced stereoselectivity in aldol reaction compared to small moleculel-proline. Under the optimized aldol reaction condition, the enantiomeric excess (ee) and diastereomeric ratio (dr) values of the aldol reaction product were respectively up to 90% and > 20/1. Moreover, the helical polyisocyanide catalyst Poly-2(m)can be easily recovered and reused in the aldol reaction for at least five cycles with maintained its activity and stereoselectivity. Graphic Abstract Enantioselective aldol reaction catalyzed by poly-2(m). [GRAPHICS]