Thecopolymerizationofp-diethynylbenzene（PDEB）withphenylacetylene（PhA）,4,4’-diethynylbiphenyl（DEBP）orm-diethynylbenzene（MDEB）arestudiedbyvaryingmoleratiosofmonomers.WhenthemoleratiosofPDEB/PhAarelessorequalto1/5,thecopolymersaresolubleandfusible,buttheothercopolymersareinsolubleandinfusible.Theresultsshowthatthegoodsolventofcross-linkedcopolymersisbenzeneandtheirsolubilityparameteris9.15cal0.5.cm（-1.5）.Andtheirswellability（θp）,Hugginsparameter（χ）,density(d425)andtheaveragemolecularweightsbetweencrosslinks（c）aremeasured.Itisfoundthatθpandcofcopolymersaregreaterbutd425islessthanthatofrespectivehomopolymers.IRspectrashowthatthecopolymershavetransoidconfigurationandsmallnumberofunreactedethynylgroupsexistinthecopolymers.Themechanismaboutthepolymerizationoracetylenicderivativesinitiatedby（Ph3P）2PdCl2isdiscussed.
