can you recommend me romance k-drama that have tragic story like mirror of the witch or 49 days? drama that make you hurt and cry, such thing like that... i prefer fantasy and supernatural drama, thanks

Moon Lovers: Scarlet Heart Ryeo
Empress Ki
I second Moon Lovers
uncontrollably fond
I'm sorry I love you
Marriage contract
Seven Days Queen
The princess' man
Innocent man
The Princess' Man does not have a sad ending. 
Memories From Bali (aka What Happened In Bali) - the last ep made me cry, rewatch it and cry again a few times.
Que Sera, Sera
Sad Love Story
Stairway to Heaven
Scent of a Woman (kind of)
Autumn Tale

and if you wanna try One Litter Tears it's jdrama, but crying is guaranteed at every episode.
Uncontrollably Fond 
1 Litre of Tears (it's Japanese but it fits what you're looking for perfectly, except for the fact it isn't Korean.) 
believe me ... tragic story + tragic ending = queen of ambitions 

it's sooooooooooooooooooooooooo gooooooooooooooooooooooooooooooooooooooooooooood , don't miss it 
I would add Angel Eyes. I personally didn't like the amount of sadness in it, though.
Tree of Heaven, Empress Ki, and Marriage Contract were the first things that popped into my head when I thought of dramas that made me cry--however none of these have a fantasy or supernatural element.  You still might want to try them anyway.