A high school student in China has spent three years literally shouldering the responsibility of ensuring that his physically disabled best friend gets to all his classes.

18-year-old Xie Xu met his 19-year-old classmate Zhang Chi when the pair began attending school together at Daxu High School in Xuzhou, a large city in the northern province of Jiangsu, in China.

Zhang suffers from muscular dystrophy, a condition that weakens skeletal muscle which often makes it very difficult for those with the disease to walk or carry their own weight.

18-year-old Xie Xu (left) carries 19-year-old classmate Zhang Chi (right) to school each day

Xie, who stands at 1.73 meters tall and weighs 75 kilos, decided to carry his friend around the school's campus to make sure he was able to attend all of his classes.

'The story of the two students is so inspiring and touching. They aren't family, but [Xie] has been doing this for three years,' Guo Chunxi, the vice-principal of Daxu High School told a local media outlet.

The teenagers live in dorms close by to the school, and each day Xie carries Zhang from their rooms to the school, and back again, and helps him with daily tasks such as getting meals and washing clothes.

Every now and then, Zhang is helped by Xie to the cafeteria for his breakfast.

Zhang (in blue jacket) suffers from muscular dystrophy, a condition that weakens skeletal muscle which often makes it very difficult for those with the disease to walk or carry their own weight

Each day Xie (in black jacket) carries Zhang from their rooms to the school, and back again

Both young men are hard-working students and are at the top of their class at their high school

Xie said that he carries his friend back and forth between classes, around the school, and their dorm about a dozen times each day.

Both young men are hard-working students and are at the top of their class, and are looking forward to their future studying in tertiary education.

'He's the most beautiful student. He also exerts positive influence on other students, who readily help Zhang. With their assistance, Zhang has never missed out on one single class,' the vice-principal said.