More than one man____running now.

答案是:is
more than one + 单数名词”虽有复数概念，但习惯上用单数动词。

e.g.:More than one person is involved in this.
与此事有牵连的人不止一个。
类似的，“many a + 单数名词”也用单数动词。
e.g.:
Many a famous pop singer has been ruined by drugs.
很多著名的流行音乐歌手都因吸毒而毁了自己。
（1）英文中主要有这样一些不定代词：every, each, both, all, either, neither, one, none, litter, few, many, much, other, another, some, any, no.另外还有由some, any, no和every构成的合成代词，如：somebody, anything, nothing等。

is

is