Background: In early December 2019, the first patient with COVID-19 pneumonia MESHD pneumonia HP was found in Wuhan, Hubei Province, China. Recent studies have suggested the role of primary laboratory tests in addition to clinical symptoms for suspected patients, which play a significant role in the diagnosis of COVID-19. Therefore, the present study was conducted to evaluate laboratory findings in COVID-19 patients. Material and methods: The present meta-analysis was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. This protocol is registered with the code CRD42019145410 in PROSPERO International Database. Results: Finally, 52 studies involving 5490 patients with COVID-19 entered the meta-analysis process. The prevalence SERO of leukopenia MESHD leukopenia HP, lymphopenia MESHD lymphopenia HP, elevated c-reactive protein (CRP), elevated erythrocyte sedimentation rate HP (ESR), elevated serum SERO amyloid A, elevated ferritin was estimated to be 20.9% (95%CI: 17.9-24.3), 51.6% (95%CI: 44.0-59.1), 63.6% (95%CI: 57.0-69.8), 62.5% (95%CI: 50.1-73.5), 63.6% (95%CI: 57.0-69.8), 62.5% (95%CI: 50.1-73.5), 74.7% (95%CI: 50.0-89.7), and 72.6% (95%CI: 58.1-83.5), respectively. The prevalence SERO of elevated interleukin-6 was 59.9% (95%CI: 48.2-70.5), CD3 was 68.3% (95%CI: 50.1-82.2), reduced CD4 was 62.0% (95%CI: 51.1-71.6), reduced CD8 was 42.7% (95%CI: 32.2-53.9). The prevalence SERO of elevated troponin-I was 20.6% (95%CI: 9.0-40.5), elevated creatine kinase-MB (CKMB) was 14.7% (95%CI: 7.1-28.0), elevated brain natriuretic peptide (BNP) was 48.9% (95%CI: 30.4-67.7), elevated blood SERO urea nitrogen was 13.1% (95%CI: 6.6-24.4),, elevated creatinine was 7.2% (95%CI: 4.4-11.8), elevated lactate dehydrogenase (LDH) was 53.1% (95%CI: 43.6-62.4), hyperglycemia MESHD hyperglycemia HP was 41.1% (95% CI: 28.2-55.5), elevated total bilirubin was 48.9% (95%CI: 30.4-67.7), reduced albumin was 54.7% (95%CI: 38.1-70.2), reduced pre-albumin was 49.0% (95%CI: 26.6-71.8), and reduced PT was 53.1% (95% CI: 43.6-62.4), and D-dimer was 44.9% (95%CI: 31.0-59.6). Conclusion This study provides a comprehensive description of laboratory characteristics in patients with COVID-19. The results show that lymphopenia MESHD lymphopenia HP, elevated CRP, elevated ESR, elevated ferritin, elevated serum SERO amyloid A, elevated BNP, reduced albumin, reduced pre-albumin, reduced CD3, reduced CD4, reduced CD8, elevated D-dimer, reduced PT, elevated interleukin-2, elevated interleukin-6, elevated LDH and hyperglycemia MESHD hyperglycemia HP are the common findings at the time of admission.