Abstract: Objective To study the influences of different heat shock pretreatment temperature on DNA double-strand breaks damaged by high temperature of V79 cells.The DNA double-strand breaks foci were acquired on a accurate laser-scanning confocal microscope and γ-H2AXs were incubated with anti-γ-H2AX antibodies. Methods V79 cells was cultured and divided into control group and groups with 39℃，40℃，41℃，42℃ heat shock pretreatment.After heat shock pretreatment and recover for 6 hours,cells were damaged with high temperature of 43℃and 45℃.Fixed with 4% paraformaldehyde,cells were incubated with anti-γ-H2AX antibodies overnight and subsequently labelled with goat-anti-mouse IgG conjugated with FITC for 1 hour.The DNA double-strand breaks foci were acquired on a laser-scanning confocal microscope. Results Foci images were acquired on a laser-scanning confocal microscope.DNA double-strand breaks foci in control group and groups with heat shock pretreatment have significant differences (P<0.05); ConclusionHeat shock pretreatment can decrease foci of DNA double-strand breaks induced by high temperature treatment.V79 cells can present adaptability to high temperature.