We investigate the statistical distribution of separation time DeltaT between the adjacent two Barkhausen jumps in Co films having the thickness ranging from 5 to 50 nm. By means of a magneto-optical microscope magnetometer, we determine the time-dependent magnetization curve and the separation time DeltaT between two jump events during avalanche process from the directly observed time-resolved domain evolution patterns. Through a statistical analysis of DeltaT, we find that the distribution P(DeltaT) seems to follow a power-law behavior with the same form within the error range, irrespective of the film thickness. (C) 2004 American Institute of Physics.