This lecture mainly discusses letters, diaries and self-portrait films. They are very special parts in essay films. They often have a very clear autobiographical style and the subjectivity of the author. They exist in the gap between first-person documentaries, avant-garde films and video art. The authors use films to write letters, or let films achieve their unique writing styles in the appearance of diaries, notes and self-portraits, thus shaping complex, changeable, fictional and real selves.