The result of the experiment showed that the optinized formula of orange plants special - purpose fertilizer was containing N 10%, P2O5 4%, K2O 6 %, and orange matter 25 %, or N 8 % , P205 3 %, K2O 4 % and orange matter 20% with using quantity of 3000 kg/hm^2 and 3975 kg/hm^2 the whole year. This could gain high products. The quality of oranges became better. Then the plonter benefits would be improved .