基本上没什么区别。 不过动词不定式做主语可把动词不定式提后,留it做形式主语,一般上都把动词不定式提后,留it做形式主语,因为这样不会显得"头重脚轻"如: To take a walk after dinner is good for us. =It is good for us to take a walk after dinner.而动名词做主语则不可以提后,像根本就没有听过: It is good for us taking a walk after dinner.这是个错句。