Abstract: Chlorophyll fluorescence quick variation can be used as a valuable index for evaluation of plants tolerance to environmental stresses. In order to evaluate chlorophyll quick fluorescence fluctuations of different wheat cultivars under water-limited condition, a factorial experiment with a randomized complete block design was performed in Karaj, Iran. Treatments were seven different irrigation regimes and three bread wheat cultivars with four replications. The measurements of Chlorophyll fluorescence parameters were done on flag leaves about three weeks after flowering. Photo-system II photochemical capacity was calculated from the ratio of variable fluorescence to maximum chlorophyll fluorescence (FV/FM). In addition, T1/2 and FV were evaluated and relative water content and flag leaf chlorophyll were also measured. Results showed that different irrigation levels affected the FV, FV/FM and T1/2 significantly (p<= 0.05), but have not any significant effect on F0 and FM. There was a significant difference between different varieties and irrigation levels in respect to chlorophyll content, RWC and grain. The means of FV/FM, FV, T1/2 and FM were declined as soil water content was decreased, but F0 was almost remained constant for all the treatments. High yielding varieties had higher T1/2, FM, FV/FM, FV, chlorophyll content and RWC values. The FV and FV/FM had highest and F0 had lowest correlation coefficients with grain yield. The existing synchronized pattern of variation in fluorescence parameters of all varieties indicates that high yielding varieties can avoid the negative effects of drought stress during grain filling period. The high correlation between fluorescence parameters and RWC confirm these findings.