To provide a saddle for tricycle capable of being ridden or operated with ease by elderly persons, ladies or men and women with anal or lumbar diseases, etc., by using a swing mechanism that is loaded to a conventional tricycle as it is and to provide the saddle for tricycle with pre adjustable height of the seat and pedal step when mounting or traveling according to the height, physique and other personal features of a rider.

The saddle is provided on a rear frame I of a rear vehicle body 2 where the swing mechanism of the tricycle is not provided and includes: a bottom plate 10 capable of being fixed to the rear frame I to be detachable; a seat base 20 composed of foaming synthetic resin body 200 with an expansion ratio of 30 or less capable of being detachably fixed to the bottom plate 10 through a top plate 30; and the seat 40 having a wide and long sitting surface 41 capable of being detachably fixed to the seat base 20 through the top plate 30.