Poly(ether)s (P-1-P-4) containing triazine groups in the main chain and pendant phenoxy groups in the side chain were synthesized by the polyaddition of bis(epoxide)s with 2,4-di-(p-chlorophenoxy)-6-(diphenylamino)-s-triazine (DCTA) with quaternary onium salts or crown ether complexes as catalysts. The polyaddition of diglycidyl ether of bisphenol A with DCTA proceeded smoothly in chlorobenzene at 120 degrees C for 24 h to give P-1 with a number-average molecular weight of 24,800 in a 95% yield when tetraphenylphosphonium chloride (TPPC) was used as a catalyst; however, no reaction occurred without a catalyst under the same reaction conditions. Polyadditions of other bis(epoxide)s with DCTA also proceeded smoothly with 5 mol % TPPC as a catalyst in chlorobenzene to produce the corresponding polymers (P-2-P-4) in high yields under similar reaction conditions.