Alkaline phosphatase (ALP) of Helicoverpa armigera Hub. (Lepidoptera; Noctuidae) (GenBank accession No. EU729322) was cloned and expressed. The target gene H.a-ALP, having an open reading frame of 1608 bp, was reverse-transcribed from cDNA by the polymerase chain reaction. The open reading frame of the target gene was cloned into the pET-32a expression vector to obtain recombinant protein in Escherichia coli DE-3 cells for the subsequent production of polyclonal antibody. New Zealand white rabbits were used for production of anti-pET-32a-H.a-ALP.