Objective: The different extron-intron recombination of horseradish peroxidase isozyme C2 (HRPC2) gene were constructed, then they were expressed in Pichia pastoris.The corresponding relationship between DNA sequence of different recombination and their biological activity were examed.Methods: The horseradish peroxidase isozyme C2 gene with its introns was amplified by PCR from genomic DNA of horseradish.The gene has 2429 bp totally whose extrons include E1 for 225 bp; E2 for 192 bp; E3 for 169 bp; E4 for 470 bp, and whose introns include I1,I2 and I3.All or part of its introns were deleted and it was recombined by multiple PCR.The recombined sequence are E1E2E3E4, E1E2E3I3E4 and E1E2 I2E3I3E4.They were linked with pMD 18-T vector and were sequenced for about 648 bp.The homology between targeted DNA sequenced and HRPC2 DNA sequence published by Fujiyama K in NCBI is about 98.5%.Targeted gene fragments were cut out by restriction endonuclease from recombined pMD 18-T vector and were inserted into expression vector pPIC9K of Pichia pastoris,and thus corresponding recombined plasmids.