两者都可以用，没什么区别，均表示“与……比较”“与……相比”，相当于when compared with sb / sth。但从使用的实际情况来看，in comparison with 似乎用得更普遍。如：

1. in comparison with 的用例

The glasses are small in comparison with the old ones. 与旧杯子相比这些杯子小些。

Jessie seemed very small in comparison with Michael’s children. 与麦克的孩子比起来，杰西显得很矮小。

Today’s economic problems pale in comparison with those of the 1930s. 如今的经济问题和 20 世纪 30 年代的相比是小巫见大巫。

They were living rather well, in comparison with people elsewhere in the world. 和世界上其他地方的人相比，他们生活得相当好。

My lack of experience put me at a disadvantage in comparison with the other candidates for the job. 因为我缺乏经验，与其他应聘者相比就处于下风。

2. by comparison with的用例

Those places are modern by comparison with Tresillian. 与特西利安相比，那些地方很现代。

The second half of the game was dull by comparison with the first. 与上半场相比，比赛的下半场有些沉闷。

The second half of the game was dull by comparison with the first. 与上半场相比，比赛的下半场打得有些沉闷。

By comparison with other European countries, car prices in the UK are very high. 和欧洲其他国家相比较，英国的汽车价格非常高。

3. 正如表示“与……比较”时，除通常用 compare with 外有时也用 compare to 一样，in comparison with 有时也可说成 in comparison to。如：

It was a tame film in comparison to some that she’s made. 较她之前拍摄的其他一些影片，这一部显得平淡乏味。

In comparison to other recent video games, this one isn’t very exciting. 和其他最新的电子游戏相比，这个游戏不太刺激。