You can use a text box to add text to your Word document pictures, but wouldn’t it be easier to place text directly on the picture itself?
MS Word will not allow you to type directly on a pasted picture, but it will allow you to add text to AutoShapes, so you can trick MS Word by converting your picture to an AutoShape, so that you can type directly on it.
Follow the steps below to learn how:
1. Launch MS Word if it isn’t already open.
2. Open the document with graphics.
3. Right-click any toolbar.
4. Select Drawing.
5. Click AutoShapes on the Drawing toolbar.
6. Select Basic Shapes from the drop-down menu.
7. Click on Rectangle.
8. In your document, click and drag where you want to position the rectangle.
9. Click the Fill Color button’s drop-down arrow in the Drawing toolbar.
10. Click Fill Effects.

11. Click on the Picture tab.
12. Click the Select Picture button.
13. Navigate to your picture and click Insert.
14. Click OK.
15. With the shape still selected, right-click the shape and select Add Text.
16. Key in your text you want at the prompt.
17. Select and right-click the text.
18. Click Font.
19. Choose the attributes you desire, such as font, font size, color, etc. from the Font dialog box.
20. Click OK.
You can place text inside the shape and add any paragraph formatting you desire.
reference by--http://www.carolscorneroffice.com