Objective: To investigate the causes of early COVID-19 complicated with platelets(PLT) abnormality, and to analyze the possible mechanisms. Methods: The case datum of early COVID-19 complicated with PLT increase or decrease was collected. (125-350) ×109/L defined as the normal level of PLT(Group C), <125×109/L was defined as the PLT decrease group (Group A), >350×109/L defined as the PLT increase group (Group B) . The data were analyzed after collected. Results: Our statistical results showed that the incidence of COVID-19 combined PLT decreased was about 11.94% and the incidence of combined PLT increased was about 9.33% at admission. Compared with Group B and C, Group A showed a significant decrease in white blood cell, neutrophil and CD4 (P<0.05). The lymphocyte in Group A and C decreased significantly, but not find in Group B (P<0.05). Compared with Group A and C, IL-4 was increased in Group B, but lymphocyte decline was not significant (P>0.05). Conclusion: PLT abnormalities occur in all patients with different types of COVID-19. It may be related to the severity of inflammation and infection, immune regulation and megakaryocyte function, etc.