The study was conducted to investigate effects of different fertilizers on ''Niitaka'' pear seedling tree performance in a controled greenhouse. The four ''Niitaka'' pear seedling trees per treatment were grown 6 months. Each pot was filled with control. rice bran (RB), coffee bran compost (CBC), and the mixture (RCC) of RB+CBC+chitin incubated compost (CIC). Root fresh weight and root activity were increased by all the organic fertilizers, especially by RCC. RCC treated trees had the highest tree growth compared to the control. The more diseased and damaged degrees on the leaf by spider mites increased leaf falling rates on all the treatment. The reduced diseased and healthy leaves were found on RCC treated trees that had better tree performance. Also, all the organic fertilized trees seemed to prevent the occurence of disease in the leaf. Theerefore, the organic fertilizer applications could be a good strategy to obtain better tree performance and maintain healthy seedlings in the nursery or young organic orchrad.