Product-by-product Input-Output structure models are well suited for specific analytical purposes, such as productivity, cost structure comparison, etc. These models show analytically the economic structure and the relations of sectors with each other in a national economy. In this study, input-output relations between agricultural and other sectors of national economy, amounted to 59, are analyzed on the data published by TurkStat (Turkish Statistical Institute), in order to determine cost (input) structure of the production and, backward - forward dependency of the sector. According to the 2002 results, agricultural activities produced the largest supply, besides second largest Gross Added Value among 59 sectors in the national economy. Agriculture was fourth biggest input user of the economy for this production on the contrary. However, 44% of the direct input requirement is provided by the sector itself and 56% of the direct inputs were bought from outer suppliers only. Mechanization Tools & Services have the biggest, 13% share, in supplying industries. This means that mechanization related products and services are the most important issues in cost composition of the agricultural production. It follows by Fertilizer & Chemicals, Trade & Finance, Transport, Electricity & Waterworks and others with 10, 7, 5, 2 and 13% shares sequentially. The shares of the outer sectors are decreased for the total inputs comparing with the direct inputs. Additionally, the total inputs required from energy related sectors have gain more importance than as the direct inputs is considered only. Agriculture has a fewer "Backward Dependency Coefficient" compared to other sectors; it is supported by mostly itself. The rank was 46 among 59 sectors. On the other hand, agriculture has a one of the highest "Forward Dependency Coefficient" compared to other sectors; it transfer most of its products to other sectors.