动名词的否定式是将否定词not置于动名词之前。若动名词为完成式或被动式，否定词not应置于整个结构之前。具体详解如下：
一、动名词一般式的否定式
动名词一般式的否定式是将否定词not置于动名词之前。例如：
Our problem is not having sufficient raw material.
我们的问题是原料不足。
His not coming made everyone present very disappointed.
他没来使在场的每个人都很失望。
Not being punctual makes him unreliable.
不准时使人觉得他不可靠。
Not being tall is not a serious disadvantage in life.
个子不高不是人生中的严重缺陷。
二、动名词完成式的否定式
若动名词为完成式，否定词not应置于整个结构之前。如：
Don't be angry with me for not having written.
我没给你写信请别生我的气。
Execuse me not having answered your letter before.
没有更早回信请原谅。
I apologize for not having kept my promise.
我没遵守诺言向你表示歉意。
三、动名词被动式的否定式
若动名词为被动式，否定词not应置于整个结构之前。如：
He doesn't like not being taken seriously.
他不喜欢被人不严肃对待。
As far as he's concerned.it's not doing something wrong that matters,but not being caught doing something wrong.
就他而论，重要的不是做错事，而是做错事不被抓住。
四、动名词复合结构的否定式
动名词复合结构带有逻辑主语，否定词应置于逻辑主语之后。如：
I'm surprised at your not having noticed.
你竟未注意到我感到吃惊。
I understand your not wanting to discuss the matter.
我理解你为什么不愿讨论这件事。
The trouble was their not being able to agree among themselves.
麻烦的是他们自己不能取得一致的意见。
Jenny's not having been trained as a dancer is her one regret.
杰妮没受过舞蹈的专业训练是她感到遗憾的事。