In the regions of high altitude in Nagano Prefecture, cabbage seedlings to be set into fields are transported from the regions of low altitude where they has been raised in beds. Experiments were carried out to determine the optimum size of seedlings to be set into the fields and the optimum time of transplanting from the warm regions in spring. The results obtained vere as follows:When large seedlings were set into the fields of the high altitude early in the season, they were apt to form imperfect flower stalks and to develop side shoots forming small heads such as Brussel's sprouts, pointed heads, or rosettes. It was not safe to plant large seedlings having six or more leaves early in the spring, because they were inclined to form flower stalks when exposed to low temperature below 10°C for more than 30 days.