The relative impacts of intrinsic and extrinsic factors on demography may be critical to the population dynamics of plateau pikas (Ochotona curzoniae) on the Tibetan Plateau.However,little is known about their demography because studies with temporal replication at the population level and adequate sampling of individuals with known fates are rare.From 2005 to 2009 we conducted a mark-recapture experiment to study the population dynamics of plateau pikas in the eastern Tibetan Plateau.Plateau pikas displayed seasonal fluctuations of density and survival.In summer,the survival of pikas was related to sex and age class,while temperature and precipitation had opposite effects on survival,and there was a one month lag in density-dependence effects on survival.Negative effects were also detected for reproductive conditions of males and females on summer survival.Winter survival (September-April) was high and stable,ranging from 86%to 90%.Plateau pika reproduce two litters per year,density,temperature,precipitation and Normalized difference vegetation indices influenced reproduction in different patterns.The concurrence of intrinsic and extrinsic factors influenced survival and reproduction of plateau pikas.