Laughing at your own jokes is not a good humor policy..... I never explain that things are jokes, if people have no response they will just miss out. A joke explained is not funny. 

even when I explain that I'm joking I still 99% get blank looks.   sometimes it makes me wonder if Chinese guys joke around,,,,,  cuz if they do, they hide it good...

I think Bill Murray said it best ~    'Lost in Translation'

Maybe you have a problem with your delivery??  I usually finish all of my jokes with either a " eh? ah? no? not funny? "  or i just cackle to myself, untill they get uncomfortable and pretend to laugh.  It might not be genuine but it does wonders for the ego.

usually when i talk about China in Australia ,I have to say I am not joking  but they keep laughing anyway

Good jokes require the listener to 1. Pay Attention,  2. Think. In China, they are taught to memorize. Essentially, do not think in order to solve the question. 

What would you categorize this as........

"Little fly upon the wall, ain't got no Mummy or Daddy to comb his hair...

he don't care, he got no hair!"

I'm not sure....but as much as I like saying it I've never had anything other than a blank look from a Chinese face.

And the same goes for the horse in the bar ordering a beer and the barman asks him why he's got a long face.

Just get a blank look.

Yeah, they don't know enough English to get the jokes. If they had the Chinese equivalent, they'd probably laugh. Since English is a second language for most Chinese, it's difficult for them to get the joke and for them to understand sarcasm.

It's much worse when you get a giggle as the only reaction on something you relly MEAN!

I usually begin "let me tell you a joke". Thing is they still miss the punchline, after you've gone silent they seem to be waiting for more.

Hahaha! I have been laughing at this question for the last 3 days its totally true! My humour is completely wasted in China!!