WithcomparisonofdemographicchangesbetweenthedevelopedEuropeancountriesandChina,thispaperhasdiscussedtheshortcomingsoftheWesterndemographictransitiontheories.Furthermore,thepaperhasproposedthedirectionofdemographictransitionandthecriteriaofsuchtransition'scompletion.Withtheestablishmentofage-structuretransitiontheory,andhelpedwithstrictdefinitionsofbothsurpluspopulationandappropriatepopulation,thepaperpointsoutthedistinctionofdemographicage-structurebetweenthosedevelopingcountriesthatareundergoingdemographictransitionandthosedevelopedcountrieswithanearcompletionofsuchdemographictransition.FinallyitconcludesthatChina'stransitionofagestructureismovingtowardsafeasibledirection.
