Having said that，是在口语交谈（spoken language）中经常出现的一个转折词（transitional phrase）。我们来看看它的具体意思及用法。
线上词典LearnersDictionary指出：““Having said that” it is a signal that they are going to say something which will contrast or disagree with what they said a moment ago. ” 即：说话的人往往把Having said that作为一个信号，提示对方：下面我说的话将会与我刚才说的内容观点相对、或产生分歧。
在中文里，Having said that，可以考虑翻译为：“说了这么多，尽管如此，不过，然而”等。
参考例句：You guys have done a pretty good job. Having said that, I still think there’s room for improvement.（你们的工作完成得不错，然而，我认为仍然有可以改进的空间）。
除了Having said that之外，that said，that being said，都可表示类似的转折意思，用法也与having said that一致。例如：I’m having my hands full right now, that said, I’ll still take time to review your proposal. （我现在忙得不可开交，尽管如此，我还是会抽时间审阅你的建议案）。
参考链接：
http://learnersdictionary.com/qa/Having-said-that-or-That-said
http://www.answers.com/Q/What_does_that_being_said_mean