If you are landing immigrants, you have to fill personal income tax return here in Canada. There is no option on where would you like to fill your tax return. However, if you filled income tax return in China, you need to get a tax document indicated the amount of income and tax you filled in China, then you can deducted those tax from your Canadian tax. Bottom line, you still need to fill tax return in Canada.
The tax rates are depends on your world wide income and your spouse income level, roughly as follow (single income family, in Canadian dollar):
 $0 - $35,000 Marginal tax rate: 21%
 $35,000 - $75,000 Marginal tax rate: 31%
 $75,000 - $120,000 Marginal tax rate: 41%
 Above $120,000 Marginal tax rate: 46.5%
The tax rates are depends on your world wide income and your spouse income level, roughly as follow (single income family, in Canadian dollar):
 $0 - $35,000 Marginal tax rate: 21%
 $35,000 - $75,000 Marginal tax rate: 31%
 $75,000 - $120,000 Marginal tax rate: 41%
 Above $120,000 Marginal tax rate: 46.5%