The extraction behaviors of Eu(III) and Am(III) from nitric acid medium by 2,6-bis(5,6-diethyl-1,2,4-triazin-3-yl) pyridine (C2-BTP) dissolved in four different room temperature ionic liquids (RTILs), viz. C(2)mim(+) (NTf2-)-N-center dot C(4)mim(+) (NTf2-)-N-center dot, C(6)mim(+) (NTf2-)-N-center dot, C(8)mim(+) (NTf2-)-N-center dot, were investigated under different conditions. The distribution ratios of Am(III) and Eu(III) in C2-BTP/C(n)mim(+) (NTf2-)-N-center dot (n = 2, 4, 6, 8) were measured as a functions of the extraction time and the concentration of nitric acid. It is found that the systems exhibit slow kinetics in extraction, and the distribution ratios for Am(III) and Eu(III) decrease with higher nitric acid concentration. The extraction mechanism is found to be cation-exchange in RTILs, which is different compared to that in molecular diluents. Though higher temperature leads to faster kinetics in the experiment, the equilibrium time still remain over 24 h. However, the distribution ratios for Am(III) are significantly enhanced at higher temperature. From the computational practice, an encouraging conclusion is that the predominant conformer of C2-BTP is greatly changed in RTILs compared with those in gas phase and molecular diluents. It is this transformation that leads to the discrepancy of the extraction behaviors with C2-BTP in molecular diluents or RTILs, and the intermolecular interactions should be well tuned to design a delighting extracting system.