Objective To investigate senescence and apoptosis of the mouse adipose-derived mesenchymal stem cells (ADMSCs) during primary culture EM>in vitro/EM> Methods ADMSCs of inguinal adipose tissue of one-month-old and 24-month-old mice, 30 of per group respectivly, were isolated and cultured primarily by differential adhesion methods. Expressions of CD73,CD90 and CD105 of P3 ADMSCs were detected by immunofluorescence technique and obsered under an fluoresence microscope. Morphology and growth status of ADMSCs were compared between two groups. β-galactosidase (SA-β-Gal) staining was used to identify the aging change of ADMSCs. The apoptosis of ADMSCs was detected by PI-Hocchst33342 double staining. Results The ADMSCs of two age groups cultured primarily in vitro were all adhered to grow and they showed the typical morphological characteristics of stem cells. The phenotypes of two age groups were ADMSCs, CD73, CD90 and CD105, positive. SA-β-Gal staining showed that proportion of the primary cultured aging ADMSCs in 24- month-old group was higher than those in the one-month-old group and higher than the primary cultured 2-7days ADMSCs in one-month-old group and in 24-month-old group were respectively. PI-Hoechst 33342 double staining showed that apoptotic proportions of primary cultured 2-7days ADMSCs in one-month-old group were (22.1±1.4)%, (36.7±1.62)%, (11.7±1.45)%, (38.4±1.57)%, (6.5±1.32)% and (11.3±1.63)%, respectively. Apoptotic proportions of primary cultured 4-7days ADMSCs in 24-month-old group were (29.4±1.72)%, (37.6±1.64)%，(19.4±1.29)% and (18.9±1.25)%, respectively. The number of apoptosis and dead cells had no significant difference. Conclusion The proliferation capability of primary cultured ageing ADMSCs is lower than that from the young age. Proportions of s