An experiment was conducted at National Horticultural Research Institute, Ibadan (latitude 7 25N and longitude 3 52 E) to assess the effects of rates and split dose application of nitrogen fertilizer on rough lemon seddlings. Four rates of nitrogen fertilizer were applied at 0,200,300, and 400 kg N/ha and in single ,two, three split doses. The experiments was laid out in a 4 x 3 factorial layout in randomized complete block design. Results obtained showed that single and split doses application did not have any significant effects on plant height at 12 weeks after fertilizer application, but had no significant effects on stem diameter. There was no significant difference among the rates of application (p=0.05). it is advisable for farmers to use 200kg N/ha for citrus seedlings production using rough lemon as rootstock.