Police certificate from FBI

Hi,

I am working in USA and H1 will expire in 2 years. I want to apply immigration to Canada. I am still not clear if I have to include police certificate from FBI in my application. FBI clearance takes several weeks or months. Can I send out the application without FBI clearance (No-crime certificate from China is included)? Will my application be accepted? (Prepare to submit it together with the medical examination).

Thanks