A novel hemoglobin-albumin complex which has high stability of the oxygenated form, has high biocompatibility, and is easily prepared (synthesized), and an artificial plasma expander and an artificial oxygen carrier containing the complex are provided. The hemoglobin-albumin complex of the invention is characterized by having hemoglobin as the core, and albumin as the shell bound via a crosslinker to the above hemoglobin. Also, the artificial oxygen carrier of the invention is characterized by containing the hemoglobin-albumin complex of the invention.