The prevalence of asymptomatic fever among children is high and may be confused with fever caused by corona. The purpose of this study is to investigate the characteristics of inflammatory factors and cardiac enzymes in children with Covid-19 hospitalized with the initial manifestation of fever without other symptoms. In this descriptive-analytical cross-sectional study, all 200 children with positive Covid-19 were hospitalized in Hazrat Ali-Asghar Hospital in Tehran between 2018 and 2019. For gathering data, clinical records and demographic information of patients were noted in the made-researcher's checklist and the collected data were analyzed using SPSS software version 24. It was found that the relationship between the degrees of fever of the patients with the number of platelets was also inverse and significant. In addition, there was a significant relationship between the degree of fever of the patients and the LDH number, ALT number and segment and lymphocyte percentage of the patients. In addition, it was found that the passing time of fever has a significant relationship with ALT and ESR in such a way that with the passage of time, there is a higher probability of seeing an increase in ESR, but in the case of ALT, it increases in a shorter period of time and decreases more after the passage of time. According to the results of the present study, in case of suspected to Covid and fever in patients, along with other tests, AST, ALT, D-dimer, and CKMB can be used to diagnose Covid, in such a way that in Covid, AST is probably normal and mentioned other tests can be higher than normal.