By using a simple tight-binding model,we study the magnetic properties of the substituted polyacetylene with lateral radicals R*.It includes the effects of π electron hopping between the alternate radicals and associated carbons on the bond order wave along the polyacetylene chain,the formation of charge density wave,and the effects of next-nearest-neighbor hoppings and electronic interactions.Our results are compared with and used to understand the ab initio calculations on the organic ferromagnet(C3H3)n,substituted polyacetylene with lateral radical R* as the organic segment CH2.