J Lo arrived at La Romana International Airport in the D.R. with her family for her first-ever concert there slated for Saturday night. Her 9-year-old twins, Max and Emme, are along for the ride, and the whole fam is staying at Casa de Campo Resort and Villas for 10 days of R&R.

As for her Dominican-American boo, Alex Rodriguez, we're told he's planning on joining her shortly.

J Lo was a hit on arrival ... easy to see why.