opinion后用on和of都可以。opinion作为名词，是可数名词，中文含义为“意见”、“想法”、“看法”、“群体的观点”、“信仰”、“专家意见”，后面可接介词on/of，固定搭配为opinion about/of/on sb/sth，意为关于某事某人的意见。
opinion的中文含义及用法介绍
opinion作为可数名词，译为意见;想法;看法;(群体的)观点，信仰;专家意见。例句有：
1、I've recently changed my opinion of her.
我最近改变了对她的看法。
2、There is a wide body of opinion that supports this proposal.
支持这项提议的大有人在。
3、They called in a psychologist to give an independent opinion.
他们征询一位心理学家的独立意见。
4、I wasn't asking for your opinion, Dick...
我并不是在征求你的意见，迪克。
5、That improved Mrs Goole's already favourable opinion of him.
那件事更加深了古尔太太对他的好印象。
6、Some, I suppose, might even be in positions to influence opinion...
有的人，我认为，甚至有可能影响舆论。
7、Even if you have had a regular physical check-up recently, you should still seek a medical opinion.
即使近期做过一次常规体检，也应当征求医生的意见。
8、Public opinion is influenced by the small elite who control the media.
舆论为少数控制着新闻媒介的上层人士所左右。
9、I didn't see enough of the play to form an opinion about it.
我对这部戏剧了解得不够，说不出什么意见。
10、A recent poll suggests some surprising changes in public opinion.
最近的调查反映民意有了出人意表的变化。
