Two field experiments were carried out at Sanhout village Menia Al-Kamh district- Sharkia province under Agronomy Department supervision, Faculty of Agriculture, Zagazig University, Egypt, during two summer successive growing seasons i.e. 2009 and 2010.The investigation aimed to study the effect of  farmyard manure (FYM) (Without, 20 and 40 m3 /fed.) and  nitrogen fertilizer levels (Without, 45 ,90 and 135 kg N / fed.) on yield and land use efficiency of maize (Zea mays L.) – soybean (Glaycine max (L.) Merr.) intercropped. Soybean variety Giza-22 was sown at 93.333 plant per fed. as pure stand and intercropping as well and maize variety TWC 324 which was sown at 23,333 plant per fed. as pure stand and intercropping (3:3) were used in this investigation included:  Pure stand of maize variety TWC 324 (23,333 plant per fed.), Pure stand of soybean variety Giza-22 (93.333 plant per fed.), maize was sowing on one side and two plants per hill (46.666 plant per fed) instead of one plant per hill in the solid plots, simultaneously, soybean was always sown and thinned as two plants in hill 10 cm apart on both sides of the ridge (186.666 plant / fed) instead of one side of the ridge in the solid plots (growing three ridges of maize in alternation with three ridges of soybean). The obtained results showed that: Grain  and seed yields of maize and soybean components significantly reduced by intercropping ,compared to the pure stand yield, However, the relative yield of those two components was 82 and 85% for maize and soybean ,respectively. Thus, intercropping efficiency i.e. economic yield advantage of the combined intercrop yield reached 67% in the maize – soybean intercrop.Grain and seed yields of maize and soybean components were significantly increased due to FYM application up to 40 m3 and N up to 135 kg N / fed.Further more,  land equivalent ratio (LER), area time equivalent ratio (ATER) and its  LER average , land equivalent coefficient (LEC) and  Agressivity (A) criterions were observed that addition of FYM did not have any significant effect on aforementioned traits in both seasons and their combined analysis. But, adding  N fertilizer have significant effect on those traits (combined analysis). However, intercropping of maize and soybean, again, was more productive than growing them separately, as can be observed from the LER, ATER  and its average values which were greater than unity and from the LEC values which were greater than 0.25 and from sign of  agressivity values which were positive for soybean component and negative for maize at three FYM and  four N fertilizer levels.