I use to work with ver.20 of kdenline, since I update the new one 21 and 22 version, I can't expand timeline height, I can only see 2 track to edit, I only know to use timeline height on setting, but I want expand it so I can use 4 and more track in newest version, or there is another way to increase timeline height?

If you move the mouse into the timeline a thin line right above the timeline icon bar (or right below the clip and project monitor control bar) should turn blue. It also has in the middle of the screen 6 small dots right above it. Grab that line and move it up or down to adjust the height of the timeline.

Hope it helps ...