The utility model relates to a comfortable writing pen which comprises a pen shell. A pen core is arranged in the pen shell. The utility model is characterized in that the pen shell is formed by an inner layer and an outer layer, and a sealed cavity is formed between the inner layer and the outer layer, and is filled with water. The utility model has the advantages that the structure is simple; the use is convenient; users can put the pen into a fridge to be refrigerated in summer, so the fingers of the users can not sweat during the use of the pen; and the users can put the pen on a radiator to be heated in winter, so the free writing incapability of the users caused by low temperature is avoided.