Abstract: The set of 6-year height and dbh data from 15-locations provenances test of masson pine was used to evaluate stability of different seed sources and determine its geographic variation pattern and ecological basis. The results showed that there existed significant seed source by site interaction,but its pattern was largely unpredictable.Comparisons of several univariate and multivariate methods suggested that stability differences between seed sources couldn’t be determined by using joint regression and principal component analysis.While Wricke’s ecovalence and Huhn’s Sli are two effective methods to discriminate stability of seed sources.The stability appeared to be related to the latitude of the seed source,but not to longitude and altitude of seed source.The temperature of seed source was found to be a main reason for this geographic pattern.The seed sources from Yudkai and Nanling mountain areas were of high growth and low stability and better adapted to good sites.The seed sources from Wuyi and Dalou mountain areas are worth the extension and use because they had higher growth rate and average stability and adaptability.Those seed sources from the Northern were of low growth rate and high stability and better adapted to poor sites. The results suggest that the efficient discrimination of seed source differences be achieved through intensive field testing at good sites.