This paper aims to analyze the developmental tendency of intelligence of Korean by Cattell's theoretical model that intelligence is divided into fluid intelligence and crystallized intelligence, characterize the factors influencing the developmental tendency, and examine whether Catell's model can be applied to Korean. For these aims, the relation between the developmental tendency of fluid and crystallized intelligence and age, sex, SES, and profession was investigated. As subject, 240 persons of 6 groups (age 12-13, 17-18, 22-24, 28-32, 36-42, 46-) were selected. Each group was composed of 40 persons, male and female in half. To measure the fluid intelligence, CFIT(Cattell, 1966) was used and for the crystallized intelligence, verbal test and numerical test, the subtests of CAB-I (Cattell, 1966) was used. By the trend analysis technique, the developmental tendency of intelligence was investigated, and by Two-Way ANOVA, the difference of developmental tendency between sex, SES, and profession was examined. the Multiple Regression Analysis was used to characterize the effect of SES, sex, and profession on the development of crystallized intelligence. The results of this study are as follows. 1. Most studies on the development of intelligence have reported that human intelligence develops during the period of young and during adulthood it is decreased. But, this study concluded that if we study human intelligence divided into subarea, we can find that there are some areas in human intelligence whose development never stops and continues to develop by the period of adulthood. It is a crystllized intelligence. 2. There is significant difference between sex (p<.05) in the developmental tendency of crystallized intelligence. And the difference between SES in not significant before age 24, but after age 28, there is significant difference between SES (p<.05). 3. Catell's intelligence theory said that the crystallized intelligence was influenced by the acquired elements, that is, education, culture and etc. rather than the hereditary elements. And it was conformed that this theory could be applied to Korean. Therefore, it must be considered in our education that human growth and development should be viewed through the life span perspective.