The 15 year old has been with the Catalan club since the age of seven.
However, according to Goal.com, Arsenal have convinced the left-back to sign schoolboy terms with the Gunners before penning a professional contract when he turns 16 next March.
Fabregas and Bellerin are among those that have moved to Arsenal from Barcelona in similar circumstances in recent years.
The London side have beaten Premier League rivals Liverpool to Lopez's signature.