The interference fringe pattern of Gaussian distributed femtosecond la ser pulses with frequency chirping is studied in this paper.Holograms in three cases of only ob ject pulse with frequency chirping,reference pulse with frequency chirping and the two pulses w ith the same frequency chirping together are simulated respectively and the carrier phases are recons tructed from the holograms.By analyzing the spatial distribution characteristics of the reconstru cted carrier frequency,the influence of the frequency chirping on the interference fringe pa ttern is studied. The computer simulation results show that the frequency chirping of pulses will result in the decrease of the contrast of the interference fringe and the change of the period of the i nterference fringe.When only object beam or reference beam has the frequency chirping,the contrast of the whole hologram will decrease and the fringe period will change linearly;when bo th object beam and reference beam have the same frequency chirping,the contrast of fringe area of the interference field will decrease seriously,which will result in the sharp decrease of effecti ve recorded area of the interference field.The research is very important for the experiment per formance of femtosecond laser pulses digital holography or interference and the precision of digital reconstruction in phase measurement.