In　order　to　fabricate　fibrous　eutectic　Si,　the　selective　etching　of　industrial　Al-Si　eutectic　alloys　directionally　solidified　at　different　growth　rates　and　modified　by　different　amounts　of　Sr　was　studied.　Flake　eutectic　and　fibrous　Si　were　obtained　by　selective　etching　of　non-modified,　Sr-modified　or　directionally　solidified　Al-Si　eutectic　alloys.　The　optimal　amount　of　Sr　for　fabricating　branching　eutectic　Si　was　0.04-0.07%.　Through　directional　solidification　with　a　high　enough　growth　rate　(more　than　200　mu　m/s),　lamellar　eutectic　Si　transforms　to　fibrous　eutectic　Si　for　use　in　non-modified　Al-Si　eutectic　alloys.　The　potentiodynamic　polarization　and　cyclic　voltammetry　methods　were　used　to　test　the　corrosion　behavior　of　non-modified　and　Sr-modified　Al-Si　eutectic　alloys.　With　a　constant　potential　of　0.5　V　in　HCl　solution,　non-modified　Al-Si　eutectic　alloys　displayed　initial　pitting　corrosion　and　subsequent　spalling　corrosion,　and　0.04%　Sr-modified　samples　displayed　uniform　pitting　corrosion.　Compared　with　non-modified　Al-Si　eutectic　alloys,　Sr-modified　samples　displayed　better　corrosion　resistance　with　lower　current　density　and　shallower　pit　depth　during　the　same　etching　conditions.