Peripheral blood stem cell (PBSC) collection has been increasingly more popular than bone marrow donation, but little side effects induced by hemogram variation of donors for PBSC collection were reported. The peripheral blood cells were counted pre- and post-collection of PBSC from 166 allogeneic-related donors. Donors' hemoglobin concentration decreased from 144.95 (±16.175) g/L to 139.12 (±13.684) g/L (P < 0.05) and platelet counts decreased from 234.51 (±60.925) × 10(9)/L to 93.00 (±28.439) × 10(9)/L (P < 0.001) after sequential PBSC collections. The anemia condition was weakly correlated (r = 0.297, P < 0.02) and the decrease of platelet counts was strongly correlated (r = 0.719, P < 0.001) to the blood cells in the collection products. The hemoglobin concentration decrease had no significant difference in all four age groups between pre- and post-collection (P ≥ 0.05), but was significantly decreased between pre-collection and post-first collection, post-second collection (P < 0.05 and P < 0.001) in all the body mass index (BMI) groups, among which the underweight group was highly decreased. Neither of the BMI groups nor age groups indicated any statistical difference on platelet counts (P > 0.05). A slight decrease of hemoglobin and a significant decrease of platelet counts occurred after sequential PBSC collection, which was tolerable for donors younger than 60 years old. The collection characteristic of underweight persons should be fine-tuned to ensure their safety. The platelet decrease was independent of ages or BMI values.