I have problem with its cuttings...They won't root...they just dry
out...every oneof them and I've already tried with hundreds of them ...in
water, in sand and in fine soil...but nothing works...so please give me some
hints!!!

That is why most Japanese maple cultivars sold in the nursery trade are
grafted. There are a few cultivars which can be cutting grown. Brent Walston
and Bill Valavanis can probably tell you which ones. I have a cutting-grown
'Butterfly' which is doing fine. If you have a particularly nice Japanese maple
you want to propagate, you may find it easier to grow it from seed & then
choose the best seedlings. However, this doesn't work if you want to do a
multiple trunk or forest planting.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)