public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            tabControl1.Selecting += new TabControlCancelEventHandler(tabControl1_Selecting);
        }

        void tabControl1_Selecting(object sender, TabControlCancelEventArgs e)
        {
            if (e.TabPageIndex == 1) e.Cancel = true;
        }
    }

------解决方案--------------------
搞成这样也行...
C# code
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            tabControl1.Selecting += new TabControlCancelEventHandler(tabControl1_Selecting);

            tabPage2.Tag = true;
            tabPage3.Tag = true;
        }

        void tabControl1_Selecting(object sender, TabControlCancelEventArgs e)
        {
            if (e.TabPage.Tag!=null&&(bool)e.TabPage.Tag) e.Cancel = true;
        }
    }