Telescopic sliding pen

The utility model relates to a telescopic sliding pen. The pen of the prior art can not be shortened, and simultaneously the function is single with inserting and putting. The utility model is provided with three sections of casing tube pen holders which are connected in series, and a plunger with a ring is fixed on the tube head of the a pen holder; a key ring can be put on the plunger with the ring. Thus the telescopic sliding pen of the utility model can be put in the ring together with a key, and can be hung on the waist. The function that pen can also be inserted and put in a pocket is reserved, and the telescopic sliding pen is convenient for preparing and use at any place by people.