也许是这样的:

yourformName.YourLabel.Font = new Font("Arial", 24,FontStyle.Bold);

或者，如果您与表单在同一班级，那么只需执行以下操作:

Or if you are in the same class as the form then simply do this:

YourLabel.Font = new Font("Arial", 24,FontStyle.Bold);

构造函数采用不同的参数(所以选择你的毒药).像这样:

The constructor takes diffrent parameters (so pick your poison). Like this:

Font(Font, FontStyle)   
Font(FontFamily, Single)
Font(String, Single)
Font(FontFamily, Single, FontStyle)
Font(FontFamily, Single, GraphicsUnit)
Font(String, Single, FontStyle)
Font(String, Single, GraphicsUnit)
Font(FontFamily, Single, FontStyle, GraphicsUnit)
Font(String, Single, FontStyle, GraphicsUnit)
Font(FontFamily, Single, FontStyle, GraphicsUnit, Byte)
Font(String, Single, FontStyle, GraphicsUnit, Byte)
Font(FontFamily, Single, FontStyle, GraphicsUnit, Byte, Boolean)
Font(String, Single, FontStyle, GraphicsUnit, Byte, Boolean)

参考此处