The invention relates to cleaner, in particular to a sucker of a vacuum cleaner enabling users easily know the height at that time, which comprises a sucker body, a height adjusting section for adjusting the height of the body, a height display section attached with marks for indicating the existing height after adjusted by the height adjusting section, a light source section lighting for the purpose of facilitating users to easily see clearly the marks on the height display section and a display outlet formed at upper side of the body aiming at enabling users can affirm the marks from outside. With the structure as above, users can clearly see the marks, etc. on the height display section; thus preciously adjusting the height, therefore, the invention is convenient for users.