The present investigation is one part of a research work on the agricultural and processing factors affecting the quality characteristics of processed tomato products specially juice and paste. This study concerned on the influence of fertilization rate of tomato crop with potassium humate on the quality characteristics of tomato fruits based on their chemical composition and functional compounds. A field experiment was conducted on tomato cultivar; (SV 8320 TD' F1 Hybrid) were treated with potassium humate at the levels of 25, 50 and 75 kg/Fed. Chemical analysis of the full ripe tomato fruits showed that fertilization with potassium humate slightly improved the fruit contents of total solids, total soluble solids sugars and ash while, total acidity, pH, protein and fat showed no changes. Moreover, the improving effect of fertilization was more pronounced on tomato contents of the functional compounds. It was found that vitamin C, total carotenoids, lycopene, β- carotene, flavonoids and phenolic compounds considerably increased due to fertilization with potassium humate. The improving effect was more pronounced at the high levels of potassium humate. The antioxidant activity of tomato fruits was also improved as a result of fertilization with potassium humate.