Import a 3ds object

i import a model from 3d studio, and then save the scene. The next day when i opened the scene, the model was reeplaced with an empty. what is going on?

i have this problem in x file or … in loading them in scene .
i do this: smalling or bigging (Resizing) my model in 3d Studio Max and save as them or convert to …
i tail this for 3,4,… time finally i get answer.
i think my object isn’t match with my scene in size.