There are 45 Trophies that can be collected.

Bronze

A Bumpy Landing
Arrive at The Burrow with Hagrid.

A Day to Remember
Survive the events at the wedding.

A Bitter Coffee
Escape the London cafe.

An Unexpected Ally
Make peace with Kreacher and discover the criminal element.

A Difficult Case
Enter and exit Umbridge's courtroom.

A Friend from Afar
Encounter with the student and the goblin.

A Slither in the Snow
Discover the secret near the place it all began.

A Necessary Relocation
Abandon hope that a friend will return.

A Cold Dark Night
Follow the Light and face the Darkness within.

A Clue to Investigate
Piece together what has been seen to discover a direction forward.

A Desperate Betrayal
Uncover some answers in exchange for freedom.

Dragon Dodge
Escape a dragon's lair after waking the dragon!

Confusion Reigns
Cast Confundo to cause an opponent to defeat other enemies.

Got it Covered!
Cast Wingdarium Leviosa to create cover against incoming spells.

A Strong Shield
20 Protego deflects.

Quibbler Collector
Collect half of all the copies of The Quibbler.

Avid Quibbler Collector
Collect all the copies of The Quibbler.

Daily Prophet Reader
Collect half of all the copies of the Daily Prophet.

Daily Prophet Subscriber
Collect all the copies of the Daily Prophet.

Wizard's Wireless Listener
Collect half of all the Potterwatch passwords.

Wizard's Wireless Wizard
Collect all the Potterwatch passwords.

The Benefit of Experience
Increase Harry's abilities up a level for the first time.

Reached Level 3
Increase Harry's abilities to level 3.

Reached Level 6
Increase Harry's abilities to level 6.

Defeated 100 Enemies
Defeat 100 enemies in Story Mode.

Defeated 250 Enemies
Defeat 250 enemies in Story Mode.

Ron's Saviour
Defeat 35 Acromantula.

First Showing
Post a result online for a Challenge for your Friends to compare.

Comprehensive Showing
Post a result online for every Challenge for your Friends to compare.

Survivalist
Get a 5 star rating on any Hard Challenge!

Friendly Rivals
Compare your ranking on any Challenge with a Friend on your Friends list.

Defender against the Dark Arts
Complete on Easy.

Silver

A Valiant Friend
All but one live to fight another day.

Wand-master
Use every spell in the game successfully at least once.

Liquid Experience
Use all available potions in the game successfully.

Reach Level 10
Increase Harry's abilities to level 10.

Reached Level 15
Increase Harry's abilities to level 15.

Defeat 500 Enemies
Defeat 500 enemies in Story Mode.

Expert Aim
50 quick Stuns.

From Under the Cloak
50 stealthy Stuns.

Auror Material
Complete on Medium.

Gold

Reached Level 20
Increase Harry's abilities to level 20.

Defeated 1000 Enemies
Defeat 1000 enemies in Story Mode.

Order of the Phoenix Recruit
Completed on Hard.

Platinum

Merlin First Class Candidate
Unlock all trophies.

http://www.ps3trophies.org/game/harry-potter-and-the-deathly-hallows-part-1/trophies/