The 44-year-old woman was stabbed four times in her chest and stomach in an argument last week with her 56-year-old husband, who suspected she was seeing another man.
The man then put his wife in a car, drove to a remote rugged area in the northeastern county of Goseong and pushed her off the cliff, a senior detective told AFP, without elaborating on the sequence of events.
Media reports said the man initially planned to take his wife to hospital by car after the stabbing, but changed his mind and pushed her down the cliff when he saw she was motionless.
But she regained consciousness the following day, climbed back up the cliff and was rescued by a passing driver. Her fall is believed to have been broken by thickets of grass and brushwood.
"It was like a miracle that she survived multiple stab wounds and the fall," the defective said on condition of anonymity, adding the husband has been arrested. The couple married early this year.