Nowadays,　SAR　Interferometry　(InSAR)　is　a　technique　to　generate　digital　elevation　models　from　space.　[1]　The　phase　image　unwrapping　is　the　most　important　step　in　processing　the　interferometric　SAR　data.　Goldstein＇s　branch-cut　algorithm　is　the　most　classical　one.　It　is　about　the　connection　of　residues　with　branch-cut　lines　to　neutralize　their　charges　so　that　the　integral　path　can＇t　stride　over　the　branches　in　the　process　of　phase　unwrapping,　thus　avoiding　pervasion　of　error.　However,　this　connection　always　brings　about　numerous,　lengthy　and　even　closed　branch-cut　lines　that　can　not　be　unwrapped,　especially　when　many　residues　exist.　This　paper　presents　an　optimized　minimum　spanning　tree　phase　unwrapping　algorithm,　and　described　the　implementation　in　detail.　It　is　expected　to　remove　the　redundancies　of　the　branch-cut　tree　accurately　and　ensure　the　effectiveness　of　phase　unwrapping.　©　2006　IEEE.