Pd/Al alloys have very interesting properties from the point of view of their possible application in heterogeneous catalysis. Preparation of small heteroepitaxial Pd/Al alloy particles opens a new way in studies of the influence of Pd/Al crystallographic structure on the alloy catalytic properties. Pd/Al alloy particles were grown by the molecular beam epitaxy method. Their crystallographical structure was controlled by reflection high energy electron diffraction (RHEED). It was found that Pd deposited on epitaxial 3D Al particles grown on KCl is intermixing with Al. This process is accompanied by the variation of lattice parameter from the Al value to the Pd one.