Effect of unicocazole  soil application on vegetative growth , flowering , sex ratio , fruil set , yield and fruit quality of mango cv. Langra were assessed in the season of application ( 1996/97 ) and in the following season ( 1997/98 ) uniconazlle doses at 0.0, 2.5 , 5.0 and 10g / tree were given twice during the first week of  November , 1996 and March , 1997 results indicated that  all uniconazole treatments suppressed vegetative flushing and reduced shoot length and leaf area than the control in both “ on"  and off – years . Uniconazole application advanced the time of flower bud opening especially in the season of application. Uniconazole treatments significantly improved the percentage of flowering shoots , sex ratio , fruit set and retention and fruit yield compared to the control  in both “ on and off – years. All uniconazole doses decreased average fruit weight than the control, the smallest fruit weight was produced with (10 g / tree). uniconazole application increased TSS and vitamin c in the fruit juice , while acidity , reducing and total sugar were not significantly affected , It could be concluded that 5 g/tree of uniconazole was superior than 10 g/tree concerning most of the studies traits .