Doping Li atom into higher flexible cyclic polyamines with many amine unit petals (ethyleneimine) forms the n-petal-shaped Li-doped cyclic polyamines (n ) 3-5). Three structures, referred to as three-petal-shaped Li-[9]aneN3, four-petal-shaped Li-[12]aneN4, and five-petal-shaped Li-[15]aneN5, with all-real frequencies are obtained at the MP2/6-31+G(d) level.