This occasional paper on Japan is one of a series setting forth the nature, scope, and accomplishments of population activities in specified countries. Here, an overview is given of population characteristics and growth patterns, the relationship of population growth to socioeconomic development, and the history of population concerns and policies. Private and governmental efforts to encourage family planning are described. It is shown that population growth has been a subject of concern since the beginning of the century, with this early interest focused primarily on the relationship of population size to food supply. Declines in both birth and death rates began in the 1920's. Though fertility practices have been under voluntary control, they have been influenced by certain notable governmental actions. With the birth rate continually decreasing, there is concern in some sectors that there will be a shortage in the labor force if present fertility patterns continue. The present rate of natural increase in Japan is 1% per year, and is expected to decline further. (JLB)