Android XML Layout Auto Scale?

on different screen size, my layout becomes smaller than expected. So is there any way to make the layout keep the same ratio on all screen? in other word how can I do scaling my layout ?

I think that my layout using drawable-mdpi Instead of drawable xhdpi.

Mylayout:
[HIGH]
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
androidrientation="vertical"
android:layout_gravity="center_vertical"

[code]...