The　influences　of　the　Latent-heat　variation　with　temperature　on　solid-liquid　phase　change　processes　were　studied　numerically.　The　results　showed　that　the　main　influence　factors　on　the　solid-liquid　phase　change　process　with　a　variable　latent　heat　are　Stefan　number,　relative　thermal　conductivity,　relative　thermal　diffusivity　and　dimensionless　phase-change　temperature　width.　As　a　constant　substitutes,　which　results　in　less　error　for　predicting　the　melting　time.　The　average　latent　heat　over　the　phase-change　temperature　width　is　used.