This work was carried out of private farm located in Qalabshu, Gamasa District, Dakahlia Governorate, Egypt, during the early summer plantings of 2017 and 2018 to study the effect of different sources of organic manures and different levels of humic and fulvic acid on growth, flowering, yield and its components and sugar in fruit of watermelon plants (Citrullus lantus L.) c.v. Romero grafted on Shantosa species. Twenty two treatments were designed in complete randomize block system with three replications, The treatments consisted of (FYM, Compost, Chicken manure and mix between them) in presence of 2 and 4 kg for each humic and fulvic acid comparing to the control. The  results  obtained  shows  that there were  significant  differences  among  treatments  in most parameters  during  the two seasons. All organic sources increased all parameters and found that the highest significant values of leaf area, dry weight, number of male and female flower as well as average weight of fruits, number of fruits, dry matter, total yield, reducing , non reducing and total sugar of fruits were recorded with application of (FYM + compost + chicken manures) in presence of 4 kg humic and 4 kg fulvic acid.