A catalase-inorganic hybrid nanoflowers (Cat-HNFs)-based colorimetric platform was prepared for visual detection of hydrogen peroxide (H2O2). Catalase via coordination was self-assembled and embedded in the copper phosphate crystals by sonication. Under the designed colorimetric system, Cat-HNFs showed linear absorbance responses toward H(2)O(2 )in the concentration range of 1 mu M to 1 mM, and the detection limit was 1 mu M. Compared to free catalase, Cat-HNFs exhibited enhanced activity and stability for H(2)O(2 )detection. Moreover, after 5 cycles via centrifugal recovery, Cat-HNFs still remained 68% of their initial activity. The detection result in human serum suggested Cat-HNFs can be a promisng candidate for the detection of H2O2 in biomedical field.