Apl planned to stage the concert Thursday evening in Manila during a brief trip to the country.
"I just want to tell everybody that my heart goes out to you guys and I will try my best to help out," he told reporters aheadof the event.
A Los Angeles resident whose real name is Allan Pineda Lindo, apl said he was concerned when he saw television footage of the devastation and decided to make a brief visit.
The worst flooding in 40 years struck the rice-growing northern Philippines and the capital Manila late last month when a typhoon after a storm dumped heavy rains that triggered landslides and inundated towns, killing 712 people and affecting more than 7 million.
In addition to a concert with local artists, apl brought canned goods from California, donated cash and appealed for more money for victims from around the world.
The hip-hop singer, who was adopted at 14 and moved to the United States, said he remains proud of his roots.
Even before his storm outreach, apl was involved in projects in his native country.
He recently performed in a music video, created in partnership with the Philippine Department of Tourism and MTV Asia, singing a new rap song, "Take U to the Philippines," which features the country's white sand beaches, mountains and bustling cities.
"I love our culture, and you know I wanna share that all over the world," he said. "I'm not ashamed of who I am, I'm very proud to be Filipino."
He has also launched his own music label, Jeepney Music, which he hopes will provide a platform for emerging Filipino music talent.
Participants can sign up and upload original music on the MTV Emerge Web site. Anyone can vote online to choose the finalists, who will be evaluated by a panel of judges including apl. Artists with the most talent and potential will be announced in November, when apl returns to Manila for another benefit concert.
The winner will receive a one-year recording contract with Jeepney Music.
"This is my way of giving back," he said.