因为用数字$$0$$，$$1$$，$$2$$，$$3$$可以组成的三位数有：$$120$$、$$102$$、$$210$$、$$201$$、$$310$$、$$130$$、$$301$$、$$103$$、$$230$$、$$203$$、$$320$$、$$302$$、$$123$$、$$132$$、$$213$$、$$231$$、$$321$$、$$312$$，所以一共有$$18$$个不重复的三位数，  故选$$\text{B}$$． 
用数字$$0$$，$$1$$，$$2$$，$$3$$能组成个数字不重复的三位数． 
  - $$24$$ 
  - $$18$$ 
  - $$12$$ 
  - $$6$$ 