Due to plant migrations there is a need for assigning indigenous or allochtonous status to incoming species, so that they are more easily monitored and in order to anticipate the consequences of migration. Indigenous plants are those that have evolved in a particular area or have migrated there naturally, without human influence. Non-native species have settled in new areas because of accidental or intentional actions of humans, and are divided according to the time of arrival into archaeophytes (migrated before 1500.) and neophytes (migrated after 1500.). The CSR theory was established by British ecologist J. P. Grime, and describes environmental strategies of plants under the influence of external limiting factors, which are divided into two categories. The first category, stress, encompasses all factors that limit the production of plant material, while the second, disorder, causes its partial or total destruction. The goal of this research is to analyze CSR strategies of indigenous and non-indigenous flora. The majority of the flora and native species are determined as CS and CSR strategists, while non-native species are mainly represented by CR, R and C strategies. With this work, amount of available data on CSR strategy and status on origin of Croatian flora has been significantly increased presenting good foundations for analyses and further research.