Silver clusters in the size range of 170-310 were optimized with a modified dynamic lattice search (DLS) method. Considering the computational complexity, only 21 clusters of several tens and magic numbers of atoms were investigated. The interaction of silver atoms is modeled by the Gupta potential. Results show that, between the 21 clusters, nine fcc and twelve m-Dh structures are obtained. Compared with the structures adopted by Ag-13 to Ag-160, the main motif is still m-Dh in the range of Ag-170-Ag-310, but the ratio of fcc structures obviously increases. It can, therefore, be deduced that the fcc motif is more stable for larger size silver clusters. (C) 2008 Elsevier B.V. All rights reserved.