The thesis' purpose is to analyse the evolution of Green Party between 2006 and 2010. Thesis is concentrated on the period when the party recorded under the leadership of M. Bursik its greatest electoral success and managed to not only exceed the electoral clause to enter the Chamber of Deputies, but also participate in forming a government together with the ODS and the KDU - CSL. Soon it became clear that the party was splitted in opinion and there was a struggle between realists, realizing that if they wanted to enforce their policies they would have to accept many compromises, and ecological radicals, who wanted to impose all or nothing. The thesis also describes the work of the Green Party in government and growing conflicts between members of Party, which resulted in the establishment of intra-party fraction "Democratic challenge" and consequent elimination of MPs O. Zubová and V. Jakubková of the Green Party parliamentary group. Particularly, intraparty conflicts and the inability of its President M. Bursik to unite the party meant a slow but steady decline in party preferences. This observation was confirmed by the electoral failures in regional elections and following elections to the European Parliament, after whichM. Bursik resigned. But finally even his successor O. Liška didn't manage...