Rice production in Indonesia has been mainly paddy-field, not up-land cultivation. The use of neither tractor nor power tillers has not been widely spread. Manual soil preparation has been the staple method through all stages of rice cultivation. The initial preparation of the paddy-field is done with a hand hoe. A wooden moldboard plow drawn by buffalos is then used. After that a harrow is used for leveling the field as the final stage of soil preparation. This combination of hoe, plow and harrow is to be observed throughout the country. Various types and shapes of plow are common. The shape of the moldboard plows is defined by sophisticated three-dimensional curving lines and are classified curve, half-curve and cylindrical type. A heavy twisting type of moldboard is not adopted in a clayey soil (N. Kawamura, 1951). Designs are adapted to fit varying parameters such as soil constitution, soil water content and traditional modes of farming. In three districts near Bogor, we investigated the relation between the shape and type of moldboard plow in use and varying types of soil in the paddy-fields. The clay content appears to be the dominant determinant of plow shape. We believe our study of the relation between plow form and soil type could contribute to the design of a standard moldboard plow.