My 2years green card will expire by next year january, and i have to send my paper work this week. I got two letters from my friends, but one of them did not notorise the letter. I just want to know if i can send the unnotorize letter with the notorized one.

Can you get them to resend a notarized version or get another one from another friend?

If you choose to send the affidavits (from what I've read, they're recommended but not required), you need a minimum of two and they both need to be sworn and notarized.

If you submit statements or affidavits, they are required to be notarized. BUT ... this is not REQUIRED documentation ... just 1 of several different way to prove continuing marriage!

Note that even a notarized letter is not what the I-751 instructions ask for -- they ask for a sworn affidavit.

A "notarized letter" only means that the notary has verified that the signature on the letter belongs to the person who made the signature.

A sworn affidavit means that the notary has not only verified the signature, but also has (ostensibly) administered an oath to the affiant, who swears by virtue of the affidavit that the facts set forth therein are true.

So a letter that is simply notarized has no probative weight whatsoever because it is unsworn.

I suppose what you are sending in is better than nothing, but if you are relying on the letters because you are light on other types of evidence, I would strongly suggest holding off until you get sworn affidavits from your friends. (You can find an example affidavit by clicking here -- just plug in what was written in each letter into numbered paragraphs.) If you are OK with other evidence, you might as well send the letters as is because they are not going to make a difference.