A novel hybrid algorithm Quantum Immune（QI）

which combines Quantum Algorithm（QA） and Immune Clonal Selection（ICS） Algorithm

has been presented for dealing with multi-extremum and multi-parameter problem based on AB off-lattice model in the predicting 2D protein folding structure.Clonal Selection Algorithm was introduced into the hyper-mutation operators in the Quantum Algorithm to improve the local search ability

and double chains quantum coded was designed to enlarge the probability of the global optimization solution.It shows that the solution mostly trapped into the local optimum.To escape the local best solution the aging operator is introduced to improve the performance of the algorithm.Experimental results show that the lowest energies and computing-time of the improved Quantum Clonal Selection（QCS） algorithm are better than that of the previous methods

and the QCS is further improved by adding aging operator to combat the premature convergence.