Abstract: Degradation Dynamics of Cry1Ab insecticidal protein within transgenic Bacillus thuringiensis corn seedling debris in field Xing Zhen-juan, Wang Zhen-ying*, He Kang-lai, Bai Shu-xiong (State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100094, China) Abstract: The degradation dynamics of Cry1Ab insecticidal protein within transgenic Bacillus thuringiensis corn seedling debris of events MON810 and Bt11 in field were investigated and compared..Results showed that the degradation of Cry1Ab toxin in transgenic corn seedlings were gradual and degraded rapidly The Cry1Ab insecticidal protein in Bt11 corn seedling debris could not been detected, but small amount of Cry1Ab toxin in MON810 could still be detected when the corn seedling decayed completely 50 days after picked off, The speed of degradation were significantly different within the same time between the two events. The Cry1Ab insecticidal protein in corn seedling debris of events Bt 11 was slower than that in MON810 within the 30 days, but faster than that in MON810 after 30 days. The Cry1Ab insecticidal protein in events MON810 and Bt11 decreased to 99.81 and 100 of the initial amount, respectively.