Last night around  12A, I removed the humidity dome (stopping the green house) because there are so much leaves and there are obvious signs of roots formation. It has been 3 wks in the pot.
However, around 9A the next day, the leaves all shrivel up. SO I re-dome it.

Question: When do I remove the humidity dome? What are the signs?

-Thanks

You need to slowly acclimate the tree, a little each day.

I agree with brianm, slowly transition the tree from high humility. 

What is slow? I mean I took it off at night when there is no sun and then in the morning I put it back on. The tree is a house plant: meaning it is in the house the whole time. 

Maybe keep your dome on full time but start poking holes in it. A few more holes every few days.

poking holes: I like that idea.
any more?
Does everyone runs into this problem?

There is a learning curve to growing indoors. It is not as easy as you would think. I could write page after page if I had the time. If I can give you some advice is this. When you have lots of roots and bud break its time to remove from humidity. When you have bud break and no roots you need to keep under humidity until the roots catch up. Then you need to calculate if the roots are big enough to support current leaves. Goodluck

Easiest way to start to finish. Use a blue tub. Put potted cuttings in then put clear thin plexy glass over it. When condensation builds up crack it open about a inch and leave it like that till lits of good growth. Then open it a little more every two days. Then thats it. Put a light on top. Forgot to mention that.

I agree with Brian's advice in post #7.  I will add the following:

If you dome it so that it's very humid, you will likely experience shriveling at some point.  Therefore I limit the amount of humidity, even when I first put the cutting in a cup.  I use an upside down cup just laid loosely propped on top.  There are intentionally some air gaps between the top and bottom cup.  Also I cut holes in the bottom of all my cups.  That way when the cup is inverted on top of the other cup, there are holes in the top and there are air gaps on the bottom.  This allows excess moisture and heat to escape, but also greatly slows down the drying process so that the cutting can survive.  This way you don't ever get an extreme imbalance between top and bottom.  You don't really want an overly humid environment, you just don't want dehydration to occur at a rapid rate. 

Once I see a lot of roots, I might just slide the top cup over a bit to create a larger air gap.  No need to poke more holes in the cup.  If the air gap is large for a day or two and there are no signs of leaf withering, it's likely safe to remove the cup entirely.  Then once it goes a few days like this, you can start transition to outdoors if weather is appropriate.  I start mine in late fall so they are usually ready in the spring before the weather is.   

Thanks all:
Will do with the cup sliding thing.

Due to turgor pressure and transpiration I will remove most of the leaves. I think it leaved out more than the roots system is forming.