To take advantage of the chirality of cellulose nanocrystals (CNCs) and to develop novel chiral polymer materials, alkynylated CNCs (alkynyl-CNCs) were prepared and copolymerized with an achiral acetylenic monomer through suspension polymerization in aqueous media. The chirality of the alkynyl-CNCs was efficiently transferred to racemic helical polymer chains, by which inducing predominantly onehanded polymer helicity. Moreover, alkynyl-CNCs simultaneously acted as a comonomer and stabilizing agent, directly providing optically active microparticles (400−800 μm) constructed by chirally helical polymer chains. So the alkynylated CNCs played triple roles in our strategy: chiral source, comonomer, and stabilizing agent for performing suspension polymerizations. SEM images showed the successful formation of microparticles with regular spherical morphology, while circular dichroi** spectra demonstrated the formation of one-handed helical polymer chains and optical activity of the microparticles thereof. The present study opens new opportunities for using CNCs and for preparing novel optically active helical polymer materials.