Abstract:In order to obtain screening test strategy on imported genetically modified (GM) maize and build the multiple polymerase chain reaction (PCR) methods based on the above strategy, molecular characteristics of 15 imported GM maize were analyzed. The results show that: 1) at least one time from 15 imported GM maize based on the testing strategy putting P-CaMV 35S and T-NOS together; 2) except for MON810, at least two times can be checked out according to the testing strategy contacting P-CaMV 35S, P-ract1, T-NOS, bar, pat with PMI. Meanwhile, the multiple polymerase chain reaction system was developed and optimized. The results show that the optimum annealing temperature of the dual PCR is 58 ℃, the optimum final concentration of primers(μmol·L-1) ratio is 0.2:0.2, the optimum annealing temperature of the six-plex PCR is 60 ℃, the optimum final concentration of primers ratio is 0.2:0.1:0.1:0.1:0.1:0.05. Verification of the multiple PCR system with known samples the map showed that the amplified bands were identical with the molecular features of the GM maize. The results will provide valuable reference for the screening and testing strategy on imported GM maize.