Abstract: Imperialist competitive algorithm (ICA) inspired by the social phenomenon is a kind of novel swarm intelligence algorithms.Like other evolutionary algorithms,for multi-modal function,ICA also has slow convergence speed and is easy to fall into local optimum.International trade is the exchange of goods and services between different countries and regions and is beneficial to the development of national economy.But it has the trade surplus and the trade defi-cit in economic trade,and a country is not easy to long-standing the trade surplus. The trade deficit which must be timely adjusted,and is conducive to the healthy development of national economy.Inspired by this phenomenon,an improved ICA algorithm based on import and export trade (IICA) was put forward and a benchmark function was selected as the test function to verify the performance of the algorithm.The results show that the solution quality and convergence rate have obvious improvement.The Lennard-Jones potential problem is a potential energy minimization problem and has huge number of local minima,which is growing exponentially with the number of the atoms.So this paper applied IICA algorithm on L-J potential problem to exhibit its applicability over real-world problems.Compared with original ICA and immune algorithm,experimental results demonstrate the effectiveness of IICA in terms of convergence speed and solution quality.

Key words: Imperialist,Colony,Assimilation,Competition,Trade