Inclusion Criteria:  Patients are diagnosed by histology and pathology as pediatric malignant solid tumors (including soft tissue sarcoma, osteosarcoma, pediatric glioma, neuroblastoma, nephroblastoma, retinoblastoma, hepatoblastoma, atypical teratoid/rhabdomymoma, embryonal tumor, etc.); Age: < 18 years old; Eastern Cooperative Oncology Group (ECOG) PS score: 0-2, estimated survival >6 months; Complete clinical laboratory examination and pathological examination information of patients; Patients can be evaluated on time, and samples can be obtained throughout the whole test process; Informed consent signed by the patient or his/her legal representative shall be obtained after the patient is informed of the project;  Exclusion Criteria:  As determined by the investigator, the patient had other major diseases that might affect follow-up and short-term survival; Any social/psychological problems that the researcher determines are not suitable for the study;