Hola,el codigo seria algo asi:
Código:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim texto() As String = Split(TextBox1.Text, " ")
Dim i As Integer
For i = 0 To UBound(texto)
MsgBox(texto(i))
Next
End Sub
End Class
saludos.