canadian apply china visa from hongkong, how long does it take? requirement? for 2 week visit.

It may take 4-5 working days and you can apply for expedited service.
Basic requirements:
Passport
Visa application form (completed online and signed) and Photo
Documents showing the itinerary including air ticket booking record (round trip) and proof of a hotel reservation, etc. or an invitation letter issued by a relevant entity or individual in China.

Peter, I would not suggest you to apply for a Chinese visa at some office in Hong Kong when you can get a single entry Chinese visa on arrival at Lo Wu (Luohu) border crossing. This is a new thing, but it functions. Here I am not talking about Shenzhen visa on arrival, but about a real whole China valid visa on arrival. So, your best option is to take a train to Lo Wu (Luohu) border crossing, to be ready for a long queue and here you will be able to obtain a single entry Chinese tourist visa. I am not certain about its validity, but I would say that it is 30 days. The price for this visa for Canadian citizens is 406 CNY that you will pay at the border crossing.