# 入木三分

rù mù sān fēn

Penetrating and perceptive

## Meaning & wording

**Literally:** Penetrate three units into wood

**Register:** Appreciative · formal

[Perspective](https://chinese-idioms.yudis.dev/idioms/topics/perspective)

## When to use it

Praise sharp analysis, portrayal, or insight.

Does not merely mean detailed or lengthy.

## Understanding the expression

The image gives writing physical force: the mark seems to enter the wood rather than rest on its surface. Modern use transfers that depth to thought and description. An analysis can expose a hidden motive, or a portrayal can capture an essential feature of a character. The phrase praises insight and precision. A long explanation full of detail may still lack this quality if it never reaches the real issue.

## Examples

她对人物心理的分析入木三分。

### Traditional Chinese

她對人物心理的分析入木三分。

tā duì rén wù xīn lǐ de fēn xī rù mù sān fēn 。

Her analysis of the character's psychology is penetrating.

这篇评论把问题说得入木三分。

### Traditional Chinese

這篇評論把問題說得入木三分。

zhè piān píng lùn bǎ wèn tí shuō dé rù mù sān fēn 。

The review explains the problem with sharp insight.

演员把那份嫉妒表现得入木三分。

### Traditional Chinese

演員把那份嫉妒表現得入木三分。

yǎn yuán bǎ nà fèn jí dù biǎo xiàn dé rù mù sān fēn 。

The actor portrayed that jealousy with striking depth.

他的漫画讽刺得入木三分。

### Traditional Chinese

他的漫畫諷刺得入木三分。

tā de màn huà fěng cì dé rù mù sān fēn 。

His cartoon offers a deeply incisive satire.

## Sources & reference checks

Original explanations and examples from Chinese Idioms Almanac. Source-checked October 6, 2026.

- [CC-CEDICT · forms & pronunciation](https://www.mdbg.net/chinese/dictionary?page=worddict&wdqb=%E5%85%A5%E6%9C%A8%E4%B8%89%E5%88%86)

- [Ministry of Education · 成語典](https://dict.idioms.moe.edu.tw/idiomView.jsp?ID=58&webMd=1&la=0)

## Keep exploring

- [如数家珍 rú shǔ jiā zhēn Discuss something with intimate familiarity ](https://chinese-idioms.yudis.dev/idioms/ru-shu-jia-zhen)

- [弱不禁风 ruò bù jīn fēng Be extremely physically delicate ](https://chinese-idioms.yudis.dev/idioms/ruo-bu-jin-feng)

- [若无其事 ruò wú qí shì Behave as if nothing had happened ](https://chinese-idioms.yudis.dev/idioms/ruo-wu-qi-shi)

- [三人成虎 sān rén chéng hǔ Repeated rumor can seem believable ](https://chinese-idioms.yudis.dev/idioms/san-ren-cheng-hu)

## Keep this one close.

Save useful idioms, read offline, and revisit them with flashcards in Almanac.

[View on the App Store ](https://apps.apple.com/app/id6819590452)

[Previous idiom 如雷贯耳 ](https://chinese-idioms.yudis.dev/idioms/ru-lei-guan-er) [Next idiom 如释重负 ](https://chinese-idioms.yudis.dev/idioms/ru-shi-zhong-fu)