Spherical flowerlike hierarchical structure of ZnSe(en)(0.5) was synthesized via a solvothermal route in the NH(3)center dot H(2)O-ethylenediamine (en)-N(2)H(4)center dot H(2)O system at 180 degrees C for 24 h. The hierarchical structure is assembled from lots of regular nanosheets. The ZnSe(en)(0.5) was further converted into pure hexagonal ZnSe by annealing in a flowing nitrogen gas at 500 degrees C for 1 h with morphology preserved. The formation mechanism of ZnSe was discussed. The UV-visible absorption spectrum and PL spectrum of the ZnSe spherical flowerlike hierarchical structure were measured. In addition, photocatalytic activity of the ZnSe flowerlike structure for the degradation of methyl orange under the irradiation of the simulated sunlight was investigated. The excellent catalytic activity for the degradation of methyl orange was found and the possible mechanism of the photocatalytic activity is also proposed. (C) 2011 Elsevier B. V. All rights reserved.