Call a, b and c the dimensions of the original box. Then the surface area is 2ab + 2bc + 2ac (because there are two sides of each type ab, bc, and ac.
The second box will have dimensions a/3, b/3 and c/3. So the surface area will be: 2(a/3)(b/3) + 2(b/3)(c/3) + 2(a/3)(c/3) = [1/9] {2ab + 2bc + 2ac}.
As you can see, the surface area of the first box is 9 times the surface area of the second box.
area of the first box
--------------------------------- = 9
area of the second box