Abstract: In this study,optimal dosage of recombinant Thermomyces lanuginosus lipase produced by Pichia pastoris(PTL)based on the specific volume,crumb texture and luminosity was determined in bread making. Furtherly baking quality of bread respectively with addition of PTL,that of commercial lipase lipopan FBG(FBG)and chemical modifier diacetyl tartaric acid ester of mono(di)glycerides(DATEM)were compared,and the gluten network and flavor components were analyzed by scanning electron microscope(SEM)and head-space solid phase micro-extraction coupled with gas chromatography-mass spectrometer(HS-SPME-GC-MS). The results showed that the optimal dosage of PTL was 10~20 mg/kg,and the excessive PTL would have negative effects. PTL performed only second to FBG and better than DATEM on improving the specific volume,gluten strength and overall sensory acceptance of the bread. The addition of 15 mg/kg PTL increased the special volume of bread by 9.8% and reduce the hardness,also it made the bread achieve the maximum score in smell(6.48)and crumb texture(6.82). The results indicated that appropriate addition of PTL could effectively improve the baking quality of bread and had the specific advantages different from commercial lipase.