Abstract: The experimental studies on development of digit working memory span across the life span and its influential factors were accomplished in 1993 healthy participants aged 10 to 90 years with education of 4~17 years. The subjects were divided into 10 age groups including 3 student groups with 10~12, 13~15, 16~19 years of age and 7 adult groups with an interval of 10 years of age. The education of 3 student groups were separately 4~6 years (the students in 4~6 years of primary school), 7~9 years (the students in junior middle school) and 10~12 years (the students in senior middle school), and the years of education between the adult groups were matched (mean years of education = 11.1±3.6). The results indicated: (1) The mean of digit working memory span was approximately 6±2 in the processing load of the most simple mental-arithmetic. (2) The best performance of digit working memory span was in the group of 16 to 19 years of age ( in the group of senior middle school students), and the regressive analyses indicated that digit working memory span changed in a parabola curve with the logarithm of age in ranging from 10 to 90 years of age. (3) There was significant difference in digit working memory span between the adults aged 20~90 years of age with high education (>12 years of education) and low education (≤12 years of education). It showed that education played an important role in the changing process with age in adults for digit working memory span. (4) It was found that the processing load of mental arithmetic had an obvious effect on digit working memory span as compared with our previous result

Key words: digit working memory span, age, education, processing load of mental-arithmetic