How create a list of children term ?

Hello,

(information : i'm french and my english is very bad, sorry for that..)

I have a vocabulary with terms like :
term 1
---term 1a
---term 1b
---term 1c
term 2
---term 2a
---term 2b
---term 2c

i'd want to have a block with
-term 1a
-term 1b
-term 1c

I tried with view but i didn't success and i don't know how i can do that ?
I'm shure this question was already put but I didn't find the answer..

thank you in advance for your help (i don't if i can say that in english ?)