In　order　to　design　a　lightweight　and　high　efficiency　condenser　for　a　miniature　refrigeration　system　with　300　W　cooling　capacity,　a　mathematical　model　is　proposed　to　describe　the　heat　transfer　and　flow　in　a　parallel　flow　condenser.　A　program　was　developed　by　using　Matlab　software　to　simulate　the　performance　of　the　condenser　which　satisfies　450　W　heating　load　under　certain　conditions.　The　weight　and　pressure　drop　curves　against　the　refrigerant　flow　arrangements　and　air　velocity　have　been　obtained.　The　influences　of　different　flow　arrangements　and　air　velocity　on　the　performance　of　miniature　condenser　were　analyzed　and　the　optimum　flow　arrangements　and　air　velocity　were　obtained.