Abstract: In this paper, characteristics of the oblique im pactofcylindricalprojectileonto L Y12 alum inum Whipple shielding Conceptw ithin the firstdoorsillvalue are studiedw ith an exam ple of Whipple shield structure through experim ental investigation. So, Shielding Concept dam age behaviors w ith projectile velocity and different im pact angle ofincidence are presented. There exists a criticalangle ofincidence w ithin the first doorsillvalue ofoblique im pact. In the condition ofangle ofincidence m ore than thatofthe criticalangle, projectile ricochet debris clouds are. Oblique im pacthas the characteristic thatcanbreak up energy. It is the advantage of the shield structure.