The cultivation of fast-growing woody crops for short rotations represents a crucial step towards balancing energy needs and environmental protection. Paulownia is increasingly utilized in establishing such plantations due to its ability for rapid growth, carbon sequestration from the atmosphere, and diverse applications ranging from timber to biomass as an energy source. Research on the clone Paulownia elongata x Paulownia fortunei RBTC15 was conducted in seven plantations of different ages and planting patterns in the Požeško-slavonska county. The aim of this study is to determine the growth of woody and leaf biomass, physical and chemical characteristics, and the amount of stored carbon in the soil at the end of the vegetation period. The measurement of trunk volume of representative trees was performed using sectioning method, and the total mass of individual tree components was determined by weighing. Moisture, ash, carbon, nitrogen, hydrogen, and sulfur content were determined in laboratory. The average growth of the total trunk volume of representative trees is 0.02459 m3, and the average growth of the above-ground volume of representative trees is 0.01865 m3. The average growth of the total mass of representative trees is 17.64 kg, and the above-ground mass is 13.38 kg. The above-ground part of the tree without leaves on average stores 0.007817 t of carbon. The average amount of stored carbon leaf biomass of one tree is 0.001168 t.