Private Sub UserForm_Initialize()
Dim Sh As Worksheet
Dim Rng As Range
Dim Arr As Variant
Dim i As Long
Dim j As Long
Dim Temp As Variant
Set Sh = Worksheets("Sheet1")
Set Rng = Sh.Range("A1:A" & Sh.Range("A" & Sh.Rows.Count).End(xlUp).Row)
ComboBox1.Clear
Arr = WorksheetFunction.Transpose(Rng.Value)
For i = LBound(Arr) To UBound(Arr) - 1
For j = i + 1 To UBound(Arr)
If Arr(i) > Arr(j) Then
Temp = Arr(j)
Arr(j) = Arr(i)
Arr(i) = Temp
End If
Next j
Next i
For i = 1 To UBound(Arr)
ComboBox1.AddItem Arr(i)
Next i
End Sub