Room temperature ionic liquid (RTILs) [BMIM]PF6 was used as a new kind of binder to construct a chemical modified carbon paste electrode (CPE) and the direct electrochemistry of hemoglobin (Hb), which was immobilized on the surface of RTIL/CPE with the film of sodium alginate hydrogel, was studied by cyclic voltammetry. The presence of RTILs improved the direct electron transfer of Hb and a pair of well-defined quasi-revesible redox peaks appeared in pH 7.0 B-R buffer solution. The cathodic and anodic peak potentials were located at -0.383 V and -0.305 V with the formal potential (E0') at -0.344 V (vs. SCE). In addition the immobilized Hb showed good electrocatalytic activity to the reduction of H2O2.