This paper is dealt with genetic variation of cold tolerance of ten representative of seed sources of masson pine which were raised and planted at three locations,Tonglu of Zhejiang,Liuan of Anhui and Tongbo of Henan.The results showed that there existed marked interprovenance variations and no significant intraprovenance variations for relative freezing damage and bud set index of seedlings at all three sites.Electroconductivities of the southern,central and northern seed sources were found to performed various change patterns under different low temperature treatments or different treatment duration at the same low temperature.The correlation analysis indicated that the electroconductivities were strongly and positively related to relative freezing damage and negatively to bud set index.The high and negative correlation was be evident between relative freezing damage and bud set index.The estimated broad heritabilities of freezing damage and bud set index were 0.76~0.86 and 0.59~0.63 respectively.