The SARS-CoV-2 infection status of hospitalized children was surveyed in the department of pediatric hematology and oncology in three different hospitals of epidemic areas in Hubei, China. A cross-sectional study was performed to investigate the clinical characteristics, lung CT scan, SARS-CoV-2 nucleic acid test and serum antibodies of hospitalized children with hemato-oncological diseases from January 23 to April 24, 2020. 299 children were enrolled in this study, including 176 males (58.9%) and 123 females (41.1%), aged from 2 months to 16 years. 255 cases (85.3%) received chemotherapy or other immunosuppressive therapies, and there were 44 cases (14.7%) of other benign diseases. Nucleic acid test was performed on 258 children (86.3%) and one case was positive. 163 cases (54.5%) were tested for serum antibodies, and all of them were negative. Lung CT scan was performed on 247 children (82.6%), and 107 of them showed infectious changes. Only one case (0.33%) of COVID-19 was diagnosed in the group. The prevalence rate of COVID-19 in enrolled children with hemato-oncological diseases in Hubei was 0.33%. Immunosuppressed patients are not prone to produce related antibodies. Comprehensive protective measures and ward management can reduce the risk of SARS-CoV-2 infection in the group patients.