The emergence of the Delta variant (B.1.617.2) in Vietnam dates back to May, 2021. This variant is more contagious. Yet, few studies assessed the clinical and paraclinical presentations of COVID-19 among children. In this study, we aimed to evaluate/clarify the symptoms of COVID-19 in children. Methods: We conducted an observational analytical study from March, 2021 to August, 2021 on two groups of patients. Group 01 (n=51): patients infected by the Alpha variant (B.1.17) in Hai Duong province and Group 02 (n=204): patients with the Delta variant in Dong Thap province. Results: In group 02, the percentage of patients with clinical symptoms is 49,5%, much higher than that of group 01 (21.6%) with p<0,05. The clinical presentations among patients with Delta variant are more prevalent, including inflammation of the upper respiratory tract (38.7% - 15.1%) and fever (22.1% - 7.8%). Changes in the laboratory tests results are non specific and there is no significant difference between two groups. Conclusion: There is not much difference between Delta (B.1.617.2) and Alpha variants in Vietnam in terms of clinical and paraclinical symptoms. The majority of patients developed no illness/ infections/ or mild symptoms.