Is there any nice text book for sheaf theory for an under gradute student? Tennison's sheaf thory was too hard for me, Please help me, Thanke you very much.
If Tennison is too hard, I'm not sure this will be a better suggestion, but a good gentle introduction is Swan's The Theory of Sheaves. Another possibility is just having a look at the first chapter or so of Bredon's Sheaf Theory. Overall Bredon gets very complicated, but it has a pretty modern style and Chapter I should be pretty readable. In fact I'd recommend about the first 60 or 70 pages and then maybe just a bit of Chapter III and the first few sections of Chapter IV. That all might still be too much for an undergraduate, but I'm not sure there's anything simpler. To learn about sheaves, at a minimum you need to know some algebra and topology.