• Willing to sign the informed consent form and be able to comply with the requirements of the protocol;

• Age≥ 18 years old, ≤ 75 years old;

• Patients with solid tumors confirmed by histopathology or cytology;

• Cohort 1 requires that the patient has not used G-CSF drugs during this chemotherapy treatment;

• Cohort 2 requires patients to suffer ≥3 grade ANC reduction after the first course of chemotherapy, and there still has the risk in the subsequent chemotherapy;

• Patients planned to receive at least 2 courses of chemotherapy regimens with FN high risk or Intermediate risk with other risk factors (including, but not limited to,≥65 years-old, poor nutritional/performance status i.e., ECOG score ≥2, etc.);

• ECOG score 0-2;

• Expected survival of not less than 12 weeks;

• Neutrophil count (ANC) ≥ 2.0×109/L, hemoglobin (Hb) ≥90g/L and platelet (PLT) ≥80 × 109/L before enrollment;

• Liver and kidney function meet the following criteria: total bilirubin ≤ 1.5 times the upper limit of normal, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 times the upper limit of normal, serum creatinine ≤ 1.5 times the upper limit of normal;

• Left Ventricular Ejection Fractions≥50%;

• Women of non-childbearing potential, i.e. women who have been postmenopausal for at least 1 year or have undergone sterilization surgery (bilateral tubal ligation, double oophorectomy or hysterectomy); Patients of childbearing potential agree to use adequate contraception within 1 month prior to the start of the trial and 30 days after the end of the study: condoms, spermicidal condoms, foams, gels, diaphragms, intrauterine devices (IUDs), contraceptives (administered orally or by injection).

• The investigator judges that the patient can tolerate treatment with Efbemalenograstim alfa.