The initial motion of domain walls in Tm‐doped bubble garnet material subjected to a step change in bias field has been investigated on bubbles by transient photography and on walls by optical averaging. It was found that the average velocity of radially expanding bubble walls varied greatly during the first 20 nsec. Velocities in the range from 22 m/sec to 0.5 m/sec were observed with no correlation noted between pulses. On demagnetized stripe walls, the fast mode velocity is a maximum of 18 m/sec for about 20 nsec at 10 Oe changing smoothly to 14 m/sec for about 10 nsec at 70 Oe. Attempts to explain these results using the Walker analysis were unsuccessful. It was found that once the sample converted to the slow mode of wall motion, the fast motion could not be initiated unless the walls were at rest for some time.