The incident happened on Flight 132 from Anchorage to Portland, about 10 minutes before the plane was scheduled to land, The (Portland) Oregonian reported.
The passenger, whose name was not reported, tried to open the plane's emergency exit. He was restrained by crew members and nearby passengers, said Bobbie Eagan, an Alaska Airlines spokeswoman.
"He remained calm after he was restrained," she said, adding why the man attempted to open the door was still unclear.
"All of our emergency exits are equipped with locks that prevent people from opening a door in-flight," Eagan said. "That's important to note."
The plane landed shortly after 5 a.m. and the passenger was detained by police at PDX, CNN reported.
No one was hurt in the incident.