<HTML>The trick is to convince the visa officer that your parents must/have to come back to Canada, and do not make sense for them to stay in the US. 1) You and your family have sufficient assets to support them in Canada (statement for your stable job, salary, or tax return)
2) Your parents will be back to Canada or China definitely (return ticket to China, or immigrant paper for your parents)
3) If your parents are old, they will not be likely to stay illegally in the US. My in-law was 78 in 1995, and got visa to US easily (show our tax return, return ticket to China, and group tour receipts)
4) Join a group tour may be better for your own purpose.
As long as you are reasonable, the visa officer will be kind to issue a visa to you. Good luck.</HTML>