二者的區別
at the end of意為“在……結束時、在……的盡頭”，可用以指時間或處所，強調一段時間的結束點或某段路程的終止處，例如：
Our school held a sports meeting at the end of last year.去年年終我校舉行了一次運動會。
At the end of this street you’ll find a bookshop.在這條街的盡頭你可瞧見一家書店。
In the end意為“最終、最后”與at last 或者finally同義。例如：
In the end they caught the thief.
in the end例句：
1、In the end it was his stomach and lungs that packed up
最后，他的胃和肺衰竭了。
2、In the end you have to readjust your expectations
最后，你需要調整你的預期。
3、In the end, she sort of pushed it
最后，她幾乎是用了推的。
at the end例句
1、He parted with us at the end of the trip.
旅行結束時他和我們分手了。
2、This point is developed further at the end of this chapter
這一點在本章結尾處有進一步闡釋。
3、He's at the end of his tether.
他沒著兒了。