Pepper was used as experimental material in thisstudy，and the effects of foliar spraying of different concentrations ofchitin oligosaccharides on thegrowth，development and quality of pepper fruit wasexplored.Pot experiments were conductedin thistest，including three treatments with CK(water -soluble fertilizersolution)，J-1(1 mg/L chitin -oligosaccharide water-soluble fertilizer solution)，and J-10(10 mg/L chitin -oligosaccharide water-soluble fertilizer solution).The results showedthat different concentrations of chitin oligosaccharides sprayed on the leaves had significant effects on thegrowth，developmentand quality ofpepper:(1)J-1 and J-10 treatment significantly increased( P<0.05)the shoot freshweight，root fresh and dryweight，and the plant height and root -shoot ratio also showed the increasing trend but did not perform the significant difference level.(2)The fruit length，flesh thickness and fruit weight of pepper of J-1 and J-10 were significantly increased( P<0.05)，butthere was no significant difference for their fruit diameter and fruit shape index.(3)After spraying chitin oligosaccharide，theVc content，solubleprotein，nitratecontent，soluble sugar content and free amino acid content of pepper fruit were significantlyincreased( P<0.05)，and the increasing rate of J-10 was greater thanJ-1.The content of flavonoids and total phenols，capsaicinand dihydrocapsaicin were significantly decreased( P<0.05)，while the reduction rate of J-10 was significantly larger than J-1.(4)The correlation analysis of pepper quality showed that there was a significant( P<0.01)and positive relationship betweensolubleprotein，total solublesugar，sucrose，fructose and Vccontent.However，there was a significant and negative correlationbetween capsaicin，dihydrocapsaicin and solubleprotein，total soluble sugar，Vccontent.In conclusion，the effect of foliar spraying of chitin oligosaccharide water-soluble fertilizer solution with concentration of 10 mg/L is moreremarkable.It can promotethe growth and development of pepperfruit，increase the single fruit weight of pepper and improve the quality of pepper fruit.