The stabbing on Wednesday stemmed from a fight between two men, according to the Los Angeles County Sheriff's Department.
Authorities say the victim was harassing a woman when her male companion stabbed him in the torso and neck. He was taken to the hospital in unknown condition and the suspect accused of stabbing him was arrested.
AIR7 HD shows scene of stabbing at Mt. San Antonio College in Walnut
The woman and two men are all students at the school.
The building where the stabbing occurred was closed, but the rest of the campus remained open Wednesday. There was no threat to other students.