The safety, tolerability, and pharmacokinetics(PK)/pharmacodynamics (PD) of DA-3031 (PEG-G-CSF) following a single dose delivered by subcutaneous (SC) injection were investigated in healthy volunteers. PK/PD of filgrastim (Dong-A) following repeated dose delivered by SC injection were investigated in healthy volunteers. PK/PD from a single dose of DA-3031 and repeated dose of filgrastim (Dong-A) were compared.