Based　on　the　calculation　of　the　single-factor　impact　values　of　the　parameters　of　a　triple　stage　tower-type　of　solar　desalination　unit　by　utilizing　a　single-factor　analyzing　method,　the　influences　of　the　cost　of　solar　heating　system,　the　cost　of　hot　water　tank,　the　costs　of　desalination　unit　and　yearly　electrical　power,　the　life　time　of　solar　desalination　unit　and　the　yearly　yield　of　fresh　water,　on　the　cost　of　the　fresh　water　production　of　the　solar　desalination　unit　are　studied.　It　is　helpful　to　do　the　further　investigation　on　solar　desalination　systems　for　reducing　the　cost　of　fresh　water　production.