This thesis offers analysis of technical preconditions for establishing development plan and advancement of navigational and technical characteristics of river Sava on the basis of infrastructural and operational norms of European Agreement on Main Inland Waterways of International Importance. Existing conditions rivers not sufficient the criteria river Sava under norm of AGN agreement. Sava is suitable for international navigation and has Class IV between Slavonski Brod and Oprisovac as well as between Slavonski Šamac and the State Border with Serbia. The large part of Sava's lenght falls under Class III. For further advancement in Sava's waterway, regarding cargo traffic growth, it is recommended to meet the demands of Class Va. The problem for accomplishing class Va are 11 curvatures which don’t correspond with international navigational rules because of their radius which is under 240 metres. There are two suggestions for this problem. First one suggests the waterway to be extended to suit two-way traffic, while the other one suggests one-way traffic, with additional manouvering area for safe ship passings. Additional dredging of Sava's waterway will enable traffic of larger ship's and various cargo transportation, a therefore it would be suitable for international navigation.