Two field experiments were carried out at Sakha Agricultural Research station, during the two successive seasons of 2011 and 2012. The objectives of this investigation was aimed to study the effect of foliar application of boron (B 1gm/L), molybdenum (Mo 0.8 gm/L) and etherel (Eth.) at two levels (5 and 10 PPm) single or in combination in comparison with untreated (spraying water) as control on growth, earliness, seed cotton yield and it components and leaf chemical composition of Egyptian cotton hybrid (10229 x Giza 86) G. barbadense L.. The obtained results could summarized as follows: Foliar application of B., Mo. and Eth. significantly increased No. of flowers/plant, boll retention, earliness %, No. of open bolls/plant, seed index and seed cotton yield/fed., but plant height, No. of fruiting branches/plant, lint % and boll weight were insignificantly increased. On the other hand, spraying cotton plants with B.at 1gm/L, Mo. at 0.8 gm/L and Eth. at 5 and 10 PPm tended to increase chemical content in cotton leaves i.e.,  chlorophyll a, b %, total chlorophyll and carotene, reducing and total soluble sugar, mono-phenol, poly and total phenols. Application of B., Mo., and Eth. tended to significant effects on fiber strength, upper half length and micronaire reading in both seasons. The highest values obtained from foliage spraying of cotton plant with Eth. 10 PPm + Mo. 8 gm/L at flowering stages improved performance and yield of cotton plant.