How about doing sth?What about doing sth?

What about =How about 常用来引起一个问句,表示建议,征求意见或询问消息,意为"……好不好 ? ","……怎样 ? ".后面可以接名词,代词和动名词
例如：
I'd like some rice . What about / How about you ?
What about going to see a film ?
要说区别的话,只能从这两个词的本身来比较了.
what是疑问代词,后常常接名词代词等方面的词；而how是疑问副词,后常常形容词副词动词等方面的词.因此,当问到：
1. I am going shopping this afternoon. What about you (you是代词)? 意为：你有什么打算?
2. I haven't seen Li Ping for quite a long time. How about him(him也是代词)?意为：他近来怎么样?
3.How about going for a walk (going for a walk动词转化来的动名词)? （常用how about）