My mother who lived in Ontario just died. My brother, who is the executor has refused to show me the will.. what do I do?
It has not been filed in probate. My brother told me that my name is not on the will and I am not a beneficiary

Has the will been filed with the court to be probated? I'm not absolutely sure that in Canada it's done the same as in the U.S. but I suspect so; If my suspicion is correct, simply contact the court ("protonotary", I believe is the equivalent of a US court clerk), and ask to see it.

Anyone who is a beneficiary has the right to see it. If your brother hasn't yet filed, you can go to court and force him to file.

Estate Planning - Ministry of the Attorney General (http://www.attorneygeneral.jus.gov.on.ca/english/justice-ont/estate_planning.asp)

Frequently Asked Questions

" How can I find a copy of a deceased person's will?
Where a deceased has left a will and the deceased's personal representative has filed an application for a certificate of appointment of estate trustee with a will at the Superior Court of Justice, any person may inspect the file and obtain a copy of the will upon payment of the prescribed fee, unless a judge of the court has ordered the file sealed. The application is filed at the court location in the county or district where the deceased resided.
Fees payable to access a court file and to obtain a photocopy of a filed document may be viewed on the Ministry's website at: Court Services - Ministry of the Attorney General (http://www.attorneygeneral.jus.gov.on.ca/english/courts/default.asp#fees). "

If the will has not been probated, as your comment states, you don't have a lot of resources. However, depending on how the will is worded and property therein, the will may not have to be probated. For example, your mother may have put assets in joint with another person, your brother possibly. He, or someone else may be a beneficiary to a life insurance policy. We can't really give you a definitive answer. How are your relations with your brother? You may have to go to court to force the issue.