The present study was undertaken to compare the effects of maximal dynamic and static work on forearm blood flow. Ten untrained male students, aged 19 to 20 years, participated as subjects. The subjects continued the work at loads of 1/3, 1/2 and 2/3 maximum strength of each subject until he was no longer able to follow the regular rhythm in the dynamic work, and to contract the regular length in the static work, respectively. These six work tests were conducted separately at least one week apart to remove training effects. Blood flow of the right forearm in supine position was determined by venous occlusion method before and after exhaustive dynamic and static work. It was found that peak blood flow after exhaustive dynamic work was significantly lower at 2/3 maximum strength load than at 1/3 max, while there were no significant differences among the three work loads in the static work. In addition, blood flow after dynamic work at 1/3 max 1oad was significantly higher than the static work at the same load, but it was reversed entirely at 2/3 max load. These results suggested that forearm blood flow after maximal work in the same subject varies not only with the work load, but also with the type of work, i.e., dynamic and static, even if the work load is the same.