He was appointed as the area commander in the south after Li Hui's death where he spends most of his life pacifying the region, often with the help of Zhang Ni.

During the end of Jian'an (建安; 196–220 period), He was nominated as a xiaolian (civil service candidate) and appointed as Chief (長) of Hanchang (漢昌).

The Administrator of Baxi (巴西太守), Yan Zhi (閻芝) recruited from the counties under his juridiction, 5 000 soldiers to replace the lost ones, Ma Zhong was in charge of leading them.

[3] After Liu Bei's death in 223, Zhuge Liang opened his office as Chancellor (丞相) and appointed Ma Zhong as his subordinate commander.

After the army returned, he joined Zhang Ni as they suppressed a rebellion in Wenshan Commandery, led by Qiang tribe learders.

For his accomplishment, Ma Zhong was further entrusted with military affairs, promoted to General Who is Firm (威將軍) and enfeoffed as the Marquis of Boyang Village (博陽亭侯).

[5] During Yong Kai's rebellion, the rebels killed the Administrator of Jianing (巴西建寧), Zheng Ang (正昂) and captured his successor, Zhang Yi before sending him as captive to Eastern Wu.

[6] In 242, he was summoned to the court and charged with delivering an Imperial Order to Jiang Wan, preventing him from switching the land-based route to a water-based one from the Han River to attack the Wei-controlled Weixing (魏興) and Shangyong (上庸) commanderies.

In 244, Cao Shuang attacked Battle of Xingshi, General-in-Chief (大將軍) Fei Yi went north to resist the invaders.

Along with Huang Quan, Li Hui, Lü Kai, Wang Ping, Zhang Ni, It was thanks to their qualities that they were all well known through the empire and because they seized the opportunity given to them that they left strong legacies.

[10] Chang Qu in the Huayang Guo Zhi stated that when he was administering the south, Ma Zhong showed kindness to those afar and helpfulness to those close to him.

After Ma Zhong's death, the people of the south built a shrine in his honor and would pray to him in time of hardship.

Yan Yu (閻宇), whose courtesy name was Wenping (文平) showed ability and would easily achieve his objectives while being diligent and conscientious in the civil affairs.