It is possible to delete all my vocabulary ? Because I added some words which I do not want add.
Now I want delete them all and start from zero. Is it possible to do so?
massive* not masive
Sure, just visit the Account page and scroll down. There is an option to delete languages. This will clear all of the data, however, including Known Words, statistics, lessons taken, etc.
Alternatively, if you would like to delete individual LingQs, you can do so by going to the Vocabulary page and deleting them.
Thx for fast hint 
!!