Abstract: Total RNA was exacted from rice shoots (B5) after 48 h fed by brown planthopper,mRNA was isolated and further purified.The first and second cDNA strands were synthesized by reverse transcription and inserted into phosphorylating Uni-ZAP XR vectors.The results revealed that cDNA library BPH induced contained 1.1×10⁶ recombinants and the average length of inserts was about 1.5 kb.The tilter of the amplified cDNA library was 1.1×10¹¹ pfu/mL.This library is suitable for screening genes in low abundance.Using the EST of zinc finger protein as probe to screen the cDNA library,a full length of dof zinc finger protein with 1.4 kb was isolated and named as OsBi2.Northern blot analysis proved that OsBi2 was up-regulated in brown planthopper-fed rice.