Leonardo da Vinci's self-portrait is a sketch, and the tool used by the painter is a kind of red chalk. This painting dates from about 15 13, and is generally considered to be the last work of Leonardo da Vinci, with a width of about 33.3x21.3cm. The whole painting is smooth and refined with a pen. From this self-portrait, we can see the master's thinking ability, temperament and deep eyes full of wisdom in his later years. The painter has long hair on his face and a long beard under his chin, and every line leaves a deep impression on people. This makes us feel Leonardo da Vinci's mental state as an old man with superior intelligence. His nose and lips show strong and unyielding character and willpower. Judging from the skills displayed in this painting, it shows that the painter has unlimited creativity and expressive force. This sketch is now kept in the library of Turin, Italy.