Can I apply tourist visa from Hong Kong.

I am a Canadian citizen who was born in Hong Kong and I plan to travel to Hong Kong first and then join the local tours to visit China (since Hong Kong offer a lot more tours to see China). Can I apply for a tourist L in Hing kong once I have booked the tours to China?
If I can't do it, what do you recommend as to how I can get a tourist L under this circumstance.

Thank you very much for your assistance.

Raymond Lee