Abstract: This investigation was carried out at the Experimental orchard, Faculty of Agriculture, Assiut University, Egypt, to study the effect of CPPU spraying and pinching on cluster and berry traits of Roomy Red, as well as, effect of berry thinning and GA3 application on cluster and berry traits of Ruby Seedless grapes during 2007 and 2008 seasons. The experiment was set up as complete randomized block (CRB) with four replicates, one vine per each. Pinching of both shoots and flower clusters as well as brushing and spraying solutions were performed at full bloom. The obtained results could be summarized as follow. GA3 at 1.5 or 3.0 ppm spraying, brushing flowers cluster or 1% Urea vine foliage spraying at full bloom significantly decreased the berries number, weight and compactness coefficient of clusters compared to untreated one. All berry thinning reduced the berries number and increased the length of clusters, hence induce a pronounced decrease in compactness coefficient and produced losse clusters. GA3 at 1.5 to 3.0 ppm and Urea at 1% spraying and brushing the flowers cluster at full bloom significantly increased the berry weight, total soluble solids, reducing Sugars and anthocyanin in berry skin compared to untreated ones On the other hand, CPPU spraying of shoots and flower clusters at full bloom significantly increased the berries number, weight and compactness coefficient of clusters compared to untreated ones. CPPU spraying at full bloom gave the highest there cluster traits compared to pinching ones. CPPU spraying and pinching either shoots or flower clusters at full bloom significantly increased the berry weight and improved the chemical constituents of juice and skin anthocyanin of berries compared to untreated ones. It could be concluded that, the best methods for berries thinning of Ruby Seedless grapevines that whether GA3 at low concentration, 1.5-3 ppm or brushing the flower cluster at full bloom to overcome the adverse effects of GA3 at high concentration. Furthermore, to overcome the unfavorable phenomenon's of Roomy Red grapevine clusters, must using either CPPU 2.5 to 5.0 ppm spraying or pinching the shoot tips alone or along with flower cluster tipping at full bloom.