a great many 这个词组，之后加不加 of 均可。

不加of 说明它是限定词。加了 of 说明它是代词，而且of 后面的名词必须是特指：加the 或其他限定词，of 后面接宾格代词。例如：

a great many books （限定词）

a great many of the books （代词）

a great many of theses books （代词）

a great many of my books （代词）

a great many of them （代词）

a great many of books （误）

a great many of 的例句：

1. A great many of the bees died, and he did not find the queens.  

死了不少蜜蜂, 他却找不出蜂后。

来自辞典例句

2. A great many of new physics phenomena appear in final results.  

在最后的结果中,我们发现有很多新的物理现象出现。

3. He has read a great many of the books in this room.  

这房间的书他好多都读过了。

4. A great many of us went to the movie yesterday.  

我们许多人昨晚去看了电影。

5. Now a great many of them are out of work.  

现在他们当中许多人都失业了。

6. A great many of the flowers were white.  

那些花多数是白色的。

7. A great many ( of the ) graduates have found jobs.  

毕业生中很多人已经找到了工作。