Describe Portia in Julius Caesar.I need a little information about Portia to pay a tribute to her.

Portia gets very little stage time in Julius
Caesar, but her main scene packs quite a wallop.  She is Brutus' wife and
makes her first appearance in Act II, scene i, just after the exit of the conspirators. 
She knows that something is troubling Brutus, and she demands to know what disturbs
him.

The Roman society prided itself on its Stoicism -- the
ability to bear what life offers with strength, reason and courage.  Portia is the
poster child for this point of view, since she demands to be treated as she believes a
wife should and be granted the confidence of Brutus' thoughts.  To emphasize her
Stoicism, Shakespeare provides an odd but telling detail about Portia in this scene. 
She wounds herself to prove her loyalty and constancy to Brutus.  Lines 294
-300:

I grant
I am a woman; but withal

A woman that Lord Brutus took to
wife.

I grant I am a woman; but
withal

A woman well-reputed, Cato's
daughter.

Think you I am no stronger than my
sex,

Being so father'd and so
husbanded?

Tell me your counsels, I will not disclose
'em.

I have made strong proof of my
constancy,

Giving myself a voluntary
wound

Here in the thigh.  Can I bear that with
patience,

And not my husband's
secrets?

So, from the above
quote, you have some strong descriptive information to assist you in paying tribute to
Portia.