Sorbus borbasii 'Herkulesfürdő' plants was proliferated on MS medium with half-strength macroelements and 100 mg l^-1 myo-inositol, 20 g l^-1 sucrose, 11 g l^-1 agar-agar and 0.05 mg l^-1 IBA. Different concentrations of kinetin, metatopolin (mT, 3-hydroxy-benzylaminopurine), BA, 6-Benzylaminopurine Riboside (BAR) were tested. The main aim of our research was to find the optimal growth regulator and its optimum concentration and to determine the leaf chlorophyll content of the in vitro plants. During proliferation, the highest number of shoots (5.73) were observed in the case of using 0.5 mg l^-1 BA whereas addition of kinetin resulted in few shoots per cluster (1.2 - 1.93). The shortest leaves (6.46 mm) were seen when using 0.75 mg l^-1 BAR and the longest leaves (12.8 mm) at 0.5 mg l^-1 kinetin. The longest shoots were found when 0.75 mg l^-1 kinetin (35.86 mm) was added. The highest concentrations of citokinins (1.0 mg l^-1 BA and BAR, 2.0 mg l^-1 KIN and mT) produced fewer and shorter shoots in most cases. The highest chlorophyll content (1.396 mg g^-1 total chlorophyll) was obtained in the presence of 0.75 mg l^-1 KIN + 0.05 mg l^-1 IBA, and the lowest one (0.416 mg g^-1) was observed in case of using 0.75 mg l^-1 BAR + 0.05 mg l^-1 IBA.