which sentense is true if I ask my old frirend

excuse me-_- i have some questions.. which sentense is true if I ask my old frirend
 =.=?->>  Do you recognize me ?=.= OR Can you recognize me?

I think that both sentences are correct.

If you happen to meet an old friend, the conversation could also be:

Hi!

Hi?

Don't you remember me? OR Don't you recognize me? OR Can't you recognize me?

In spoken English, one usually uses a negative question (a question with "not") to show surprise or disappointment. You also normally use the contracted form ("don't you" instead of "do you not").

Here are some examples:

Don't you recognize me?

Haven't you finished this job yet?

Can't you speak Chinese?

Haven't you ever kissed somebody before?

* 

Here are some rules (that I have copied from a web site):

Negative questions
In the Simple Present of the verb to be, negative questions are formed by reversing the order of the subject and verb, and adding not after the subject.
e.g. Am I not awake?
      Are they not ready?

In spoken English, contractions are usually used in negative questions. In the contracted form of a negative question, the contraction of not follows immediately after the verb. For example:

Without contractionsWith contractions  Are you not awake?  Aren't you awake?  Is he not awake?  Isn't he awake?  Are we not awake?  Aren't we awake?  Are they not awake?  Aren't they awake?

It should be noted that there is no universally accepted contraction for am not. In spoken English, am I not? is often contracted to aren't I?. However, although the expression aren't I? is considered acceptable in informal English, it is not considered to be grammatically correct in formal English. In formal English, no contraction should be used for am I not.

http://www.fortunecity.com/bally/durrus/153/gramch01.html#4c

We use negative questions to show surprise, in exclamations and when we expect the listener to agree with us.

1. TO SHOW SURPRISE

Didn't you hear the bell? I rang it four times.

2. IN EXCLAMATIONS

Doesn't that house look beautiful! (= that house looks really beautiful)

3. WHEN WE EXPECT THE LISTENER TO AGREE WITH US
"Haven't we met somewhere before?" "Yes, I think we have."

NOTICE THE MEANING OF YES AND NO IN ANSWERS
TO NEGATIVE QUESTIONS:

Didn't Roberto pass his exams?
Yes. (= Yes, he passed them.)
No. (= No, he didn't pass them.)

NOTICE THE WORD ORDER IN NEGATIVE QUESTIONS WITH WHY…?:

Why didn't you lock the door? (not why you didn't lock)

Why don't we go out to Harley's restaurant? (not why we don't go)

Why can't you help me? (not why you can't help me)

Why wasn't Claudia invited to the party? (not why Claudia wasn't)
http://www.ompersonal.com.ar/omgrammar/preguntasnegativas.htm

"Do you" would be the most accepted.  

Although both would be correct by the english language itself, the way people actually speak is different.  People would say "Do you recognize me?"