The chemical mixing strategy involving molten-salt lithiation at 450°C and post-annealing at 800°C on formation of morphological replica of spinel lithium manganese oxides from nanostructured potassium-contained manganese oxides has been discussed in terms of influences of Li/Mn stoichiometry during molten-salt mixing, crystal phases and microstructure of precursory nanostructured MnO2. It is exhibited that α-MnO2 with suitable-sized one-dimensional tunnels in lattices facilitates the formation of chemical-level mixture of Li, Mn and O, and ensuring morphological retention after molten-salt lithiation. Compared to α-MnO2, the interlayer gap in δ-MnO2 crystal lattices is too large to ensure chemical-level mixture or morphology retention. It is suggested that the precursory Li/Mn ratio during molten-salt treatment should be prudently controlled, aiming to restraining excessive surface-absorption of Li and facilitating an effective Li/K exchange process. Also, one-dimensional nanoarchitectured precursory manganese oxide is advantageous over its nanoparticle counterparts on morphological retention after post-annealing process, due to its the enhanced stability against large local strains. Electrochemical measurements show that the prepared phase-pure and highly crystalline spinel-typed lithium manganese oxide nanorods in morphological replica of precursory α-MnO2 nanorods deliver a reversible specific capacity 94mAhg−1 upon 200 times of charge–discharge cycling at a rate of 10C.