A blow molding ethylene resin composition satisfies the following requirements [a], [b], [c] and [d] at the same time: [a] the melt flow rate (MFR) at a temperature of 190° C. under a load of 21.6 kg is in the range of 1.0 to 15 g/10 min; [b] the density is in the range of 955 to 970 kg/m3; [c] the number of methyl branches per 1000 carbon atoms is less than 0.1 according to 13C-NMR; [d] the tensile impact strength measured at −40° C. in accordance with JIS K 7160 is not less than 270 kJ/m2.