Background : Osteoporosis and atrophic cell pattern in Pap smear are frequent findings In postmenopausal women due to loss of ovarian function, The present study attempted to find out possible correlation between morphologic characteristics of Pap smear and osteoporosis. Material & methods: The subjects were 825 women(age from 35 to 80) who had undergone Pap smear and bone mineral density(BMD) at The Korea Association of Health Promotion, Seoul Branch, from March 8 to May 10, 2005. Pap smears from 825 women were reviewed and classified either mature cell pattern or atrophic cell pattern by their cytologic patterns, BMD were measured using LUNAR DPX MdIQ(Minster, Ohio, USA). BMD value of lumbar spine(Ll, L2,L3 and L4) were measured from 825 women and BMD value of proximal region off emur(neck NK, Wards triangle WT, and trochanter TR) were measured from 818 women and their bone status were classified as normal( T-sore:>-1.0), osteopenia (T-score: -l~<-2,5) and osteoporosis(T-score: ≤ -2.5). And age distribution of Pap smear, average T-value andfrequency ofsteoporo-sis of each region of the bone, percentage of osteoporosis of each boneregion by age group and changing pattern of percentage of osteopenia and osteoporosis in certain postmenopausal period were compared between mature and atrophic cell pattern. Results: Pap smears revealed total mature cell pattern 53,9%(445/825) and total atrophic cell pattern 46.1%(380/825), Percentage of mature cell pattern decreased from 98.2%(168/171)under 44 age group to 13,3%(17/128) over 65 age group and mature cell pattern increased from 1.8%(3/171) under 44 age group to 86.7%(111/128) oyer 65 age group. Mean T-value of each region of lumbar spine and femur of mature cell pattern were lower than that of atrophic cell pattern about -1,5. And osteoporosis has noted in atrophic cell pattern showing odds ratio Ll 13.9, L2 15.3, L3 12.0, L4 10,4, UK 6.7, WT 10.9 and TR 4.1.Atrophic cell pattern started to increase after 45 years of age and osteoporosis of a trophic cell pattern started after 55 years of age. During 50 to 64 years of age period, L3, L4 and WT revealed parallel increased of osteopenia and osteoporosis and Ll, L2 revealed decreased of osteopenia and increased of osteoporosis. nia Conclusion: Above findings suggest that atrophic cell pattern of Pap smear precedes osteoporosis about 10 years and one of predictor of osteoporosis.