The victim is a 20-year-old student from the Information Technology Faculty of a Vocational Training School in Nga Bay town, Hau Giang province.
He was snapped by a crocodile while posing in the cage in the Lung Ngoc Hoang nature reserve in Can Tho city on December 14.
The victim is now at a clinic in Can Tho city with many serious injuries in his left arm. The boy lost a lot of blood. He is recovering after a four-hour surgery.
Nguyen Hoang Tho, director of the reserve, said no security personnel were around when the students climbed in.
The Lung Ngoc Hoang nature reserve is home to many rare floral and fauna species, which are listed in the World Red Book.