This paper analyses knowledge about sustainable development and the possibility of using the cluster analysis for the Ward’s method to assess the similarity and diversity between EU member states. The authors present Ward’s methods which should be used by state authorities to improve the level of sustainable development. The methodology used allowed to share test units in four groups. Each of the groups has been characterized on basis of the available advantages and disadvantages. Most benefits had a group B and the biggest defects group C. The group A included the following countries: Estonia, Ireland, Cyprus, Latvia, Lithuania, Luxembourg, Malta, Slovenia, Slovakia. In Group B, there were 10 countries: Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, Greece, Hungary, Netherlands, Portugal. Minimum required proved Groups C and D, focusing only on the 3 Member States. The group C consisted of: Germany, Spain, United Kingdom, and Group D of: France, Poland and Italy.