The　effects　of　process　conditions　on　product　property　were　studied　in　the　synthesis　of　DCPD-modified　unsaturated　polyester　by　blocking　of　terminal　groups.　The　results　show　that　the　optimal　conditions　of　synthesis　reaction　are　as　follows:　the　total　anhydride/propylene　glycol/DCPD　ratio　is　1:1.1:0.1　-　0.16,　and　when　acid　value　is　50　mgKOH·g-1　with　gradual　addition　of　DCPD,　the　addition　time　is　1　-　2h,　reaction　time　is　about　2h.