I filed my previous year tax year i had my status as married and now this year when putting my status as married it asking for spouse sin number but she is not in canada

You can enter her SIN as 000-000-000. Don't take the Spousal Amount unless you have proof that you are supporting her.

??!

If you are married, you need to file as married. Or report your change of marital status to the CRA. 

Also, if you've gotten a divorce or became separated, you would choose one of those as a status - you can't go back to being single.