Abstract:The study of atomic structures in dense plasmas has a very important reference value for plasma diagnosis and astronomical observation. The MCDF method combined with ion sphere model are used in this work to investigate the influence of dense plasmas on the energy levels and transition parameters (transition energies, transition probabilities and oscillator strengths) of the Li-like Al ion in dense plasmas. With the increase of plasma screening intensity, the changes of the atomic structural parameters mentioned above are listed below: The energy levels of 1s22p (2P1/2,3/2) increase, but those of 1s23s (2S1/2), 1s23p (2P1/2,3/2) and 1s23d (2D3/2,5/2) decrease. The transition parameters of transitions between different principle quantum number n decrease. The transition parameters of transitions between the same principle quantum number n increase, except that of 1s23s (2S1/2) - 1s23p (2P1/2,3/2). The transition parameters of transitions between 1s23s (2S1/2) - 1s23p (2P1/2,3/2) increase first and then decrease with the rise of free electron densities. In the fine structures of one transition, the transition probabilities and oscillator strengths for △J=1 are greater, but those for △J=0 are relatively smaller.