Which is better to do bankruptcy of foreclosure?

That's kind of like asking me if I would rather you hit me in the head, or the knee cap, with a sledge hammer?

Seriously, if you can maintain the payments on you house within the bankruptcy, that would be the best option. Since the foreclosure will severely damage your credit anyway, I would avoid the foreclosure if possible.

Good luck to you!

Assuming you no longer want the property and you can afford all your other budget and debt, it would be best to allow the foreclosure and see whether the mortgagee pursues a deficiency claim against you. If it does pursue the deficiency claim, then file bankruptcy depending on other factors, such as property you may own that you can not keep under the exemptions.