The new ranking is the highest he has achieved in his career and marks a new milestone for Vietnam.
Nam is currently in Vietnam for intensive training and will participate in several Men's Futures events on clay court in China later this month.
Ly Hoang Nam of Vietnam has reached a new point in his career after being ranked 909th in the world by the Association of Tennis Professionals on February 1.
The Tay Ninh Province-born player jumped three spots from his ranking last month.
Nam is currently in Vietnam for intensive training and will participate in several Men's Futures events on clay court in China later this month.