Dynamic changes of the percentages of CD3+, CD3+CD4+and CD3+CD8+lymphocytes in mice exposed to sulfur mustard (SM). Male KM mice were exposed to saline, propylene glycol (PG) and 20 mg/kg SM by subcutaneous injection. Six animals from each group were sacrificed after SM exposure at 4 h, 24 h, 72 h and 168 h, and the spleens were prepared as a cell suspension as described in the Materials and Methods and then incubated with CD3+CD4+ and CD8+ antibodies. The percentages of CD3+(A), CD3+CD4+(B) and CD3+CD8+(C) cells were assayed with a flow cytometer (FCM). Data were presented as the mean ± SD, n = 6 for each group (A-C). *Significant difference between the PG treatment and SM exposure groups (**P < 0.01, ***P < 0.001).