The study was conducted during the 2020 and 2021 seasons at Alexandria University Alexandria, Egypt, in the Department of Flowers, Ornamental Plants, and Landscape Gardens Nursery, Faculty of Agriculture (El-Shatby). This study examined Paulownia hybrids (Paecownia elongate×Paulownia tomentosa) cultivated in 30-cm-diameter plastic pots. The study aimed to determine how different irrigation levels (40, 60, 80, and 100% of the field capacity) and chitosan ratios (0.0, 0.1, 0.2, and 0.3%), the transactions amount to sixteen, would affect the roots production, vegetative growth, flowering characteristics, and some chemical constituents of Paulownia hybrid seedlings grown in sandy soil. The irrigation level was found to have a greater effect on all of the features of Paulownia hybrid seedlings that were investigated than chitosan (soil conditioners -ratios). Additionally, the most important characteristics of the plant, include its height, number of leaves, leaves dry weight and leaves area, stem diameter and stem dry weight, number of flowers per plant, and length and dry weight of its roots. To determine the amount of carbohydrates in the leaves, the proline, chlorophyll, and relative water content, the largest amount of moisture (100 % of the field capacity) was combined with 0.1% chitosan (soil conditioners). According to the results, it is generally advised, to irrigate the cultivated Paulownia hybrid daily in sandy soil at a rate of at least 80% of the field's capacity. While, adding chitosan (soil conditioners (at a rate of 0.2% improved the vegetative growth, flowering characteristics, and root production. Also, adding chitosan at a rate of 0.1% improves some chemical analysis of the seedlings grown in sandy soil.