Objectives: This study aims to define the relationships between the sensory, cognitive and physical functions of young-old and old-old individuals. Methods: Participants were 10,451 elderly individuals aged 65 and above, raw data of a 2014 National Survey on Korean Older Persons was used. To investigate the relationships among the sensory, cognitive, and physical functions, a structural equation model was used. Results: The key analysis results are summarized as follows; 5% had poor vision function(young-old 3.5%, old-old 7.1%), 3.8% had poor auditory function(young-old 1.7%, old-old 6.7%), 33.0% had decline in cognitive function(young-old 30.9%, old-old 35.7%), 3.6% were disabled(young-old 1.6%, old-old 6.3%) and cognitive function influences physical function more greatly than does sensory function. Additionally, in the young-old groups, vision among sensory functions, attention among cognitive functions, and IADL among physical functions, turned out to be the most influential. However, in the old-old groups, auditory function among sensory functions, orientation among cognitive functions, and IADL among physical functions, turned out to be the most influential. Conclusions: This study implies that functions in the young-old and old-old individuals must be considered with all three functions—sensory, cognitive, and physical—together at the same time and that this comprehensive approach is necessary in national policy making.