The　effects　of　environmental　parameters　on　water　droplet　frozen　on　horizontal　copper　surface　under　low　ambient　temperature　and　forced　convection　were　investigated　experimentally.　The　cold　surface　temperature　is　-15.5°C　and　-19.5°C,　the　ambient　air　temperature　is　varied　in　the　range　of　-6°C　to　8.5°C,　the　relative　humidity　is　varied　in　the　range　of　50%　to　80%,　and　the　air　velocity　is　varied　from　1.0　m/s　to　9.0　m/s.　The　experimental　results　show　the　water　droplets　frozen　time　increases　with　the　increasing　cold　surface　temperature　and　decreases　with　the　increasing　air　humidity.　In　addition,　the　air　temperature　and　velocity　have　obvious　effects　on　the　droplets　frozen;　the　water　droplets　frozen　time　firstly　decreases　and　then　increases　with　the　increasing　air　temperature　and　velocity.