Experiments were conducted out to investigate cooling coefficient of a lamellar double-decker jet impingement/film structure.Blowing rate M

the ratio of the jet impingement distance to the diameter of the jet hole H/d

and the ratio of the distance between the jet hole and film hole to the diameter of the jet hole P/d were changed to study the rules of local cooling coefficient varying with these parameters.All the results show that higher cooling coefficient was achieved under larger blowing rate conditions.And there exists a proper range of H/d and P/d

which can result in a maximum cooling coefficient.It is verified that when H/d=0.5 and P/d=4

the maximum cooling coefficient can be achieved.