Objective To make better use of CBA/CaJ mice in biomedical research, the basic biological indicators of SPF CBA/CaJ mice were determined. Methods CBA/CaJ mice at six and twelve weeks of age were selected, and the main organ weights were detected. The blood physiological and biochemical parameters, proportion of immune cells were measured by full-automatic blood physiological and biochemical analyzer and flow cytometer respectively. Results Compared with the same age of male and female mice (6 or 12weeks), body weight, heart, liver, kidney weight of males were significantly higher than females (P< 0.01). Mice with the same genders, the body weight of male mice at 12 weeks was significantly higher than 6 weeks of male mice (P = 0.000). Compared the male and female mice at six weeks, blood physiological parameter showed that MCV, RDW, PLT, P-LCR, BUN and CHOL of males were significantly higher than females (P< 0.01), while MCHC of male was significantly lower than female (P = 0.000). Blood biochemical indexes showed that ALKP of male mice was lower than female at twelve weeks（P = 0.001), while CHOL was higher than female (P = 0.000). Mice with the same genders and different weeks, MCV, RDW, MCH and ALKP of twelve weeks mice were significantly lower than six weeks (P< 0.01), while BUN was higher than six weeks mice (P< 0.01). The results of blood immune cytosis showed that all mice had a certain proportion of immune cells. Conclusions The basic biological datas of CBA/CaJ mice were established. The results suggested that the cellular immune system for the CBA/CaJ mice is intact, and these indicators were affected by age and gender.