you can find the answer from here http://wenku.baidu.com/view/e88b4fc9da38376baf1faef4.html

You may well say that, but remember they can both mean "can/be able to"(See?I said they are similar……).eg. 我可以七分钟内吃十个苹果！ P.S.Developed from "allowed to", 可以 is often used as "could","may": "我可以借用你的钢笔吗？"sounds polite.

”能“——a capability, "可以”—— a right.

Thanks again 小鸡崽儿满地跑满地跑 I guess that 可以 is "allowed to" and 能 is "can/be able to".

I mean,"能“ is similiar to "can" and "可以” is similiar to "be able to"