Your plant is a Ming Aralia. A very nice plant.
I agree when you water, to do so thoroughly, but it needs to dry between waterings..not to a point the soil cracks, but the top layer should feel loose. Overwatering this plant will kill it. Also, does the pot have drainage? You don't want the bottom sitting in water. This will drown the roots only to kill plant. Ming's like occassional showers for humidity..Toni

I agree w/ Toni (Hi there!), this plant doesn't want that much water, it does need to dry out in btwn). I water mine only once a week & keep it on a pebble tray (I don't mist it), & it's just fine.

Sometimes the change of environment can lead to yellowing &/or dropping leaves, it could be that too.

By the way, no great hurry to pot it larger, they don't care for that.

Wow, thanks for the replies! I`m not sure what you would call "drainage" exactly, but the pot is a regular clay pot with a single hole in the center of the bottom. I guess we`ll start watering it a little bit less.

What`s a pebble tray?

Hi Karen...missed ya.
Wet, a pebble tray is basically what is says..a tray filled with pebbles..(S)
You'd use some type of tray w/rims/edges..set pebbles atop tray then keep filled with water..this helps create a humid atmosphere. (humidity) Toni