Based on the intrinsic behaviour of doped Co-based perovskite to generate the second phase of Co3O4, a novel strategy was developed to synthesize a hybrid catalyst consisting of La1-xSrxCoO3-delta (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) and in-situ generated Co3O4 in the presence of NaBH4. When x increased to 1.0, a well designed integration (SrCoO2.5@Co3O4) was obtained which displayed the optimal OER activity with an overpotential of 330 mV at 10 mA cm(-2), a small Tafel slope of 66.7 mV dec(-1) and terrific durability in alkaline media. This excellent performance can be attributed to the auxiliary of the in-situ generated Co3O4 for SrCoO2.5 which modifies the chemical states of Co cations, compensates for the unsatisfactory electrical conductivity of SrCoO2.5 while preserves oxygen vacancies, boosts the content of lattice oxygen and exposes more active sites. This work is expected to provide a new mind to design effective electrocatalysts towards water splitting. (C) 2019 Elsevier Inc. All rights reserved.