Excretory/secretory antigens (E/SAg) and somatic antigens (SAg) of Ascaris suum lung larvae that induce the immunoglobulin G antibodies production in Oryctolagus cuniculus experimentally immunized was determined. For this purposes, specimens of Mus musculus BALB/c were inoculated orally with infective eggs of A. suum obtained from pigs naturally parasitized in order to obtain the lung larvae. Part of these larvae was cultured in Minimum Essential Medium (MEM) to obtain E/SAg and another part was sonicated to obtain the SAg too. Both, E/SAg and SAg mixed with complete and incomplete Freund's adjuvant were used for rabbits immunization. Five weeks after the immunization, the rabbits were bled by cardiac puncture obtaining the immunosera by centrifugation, which was purified partially by saline precipitation and dialysis. By using an Western blot technique with purified immunoserum and E/SAg obtained to 20 hours and reduced with dithiothreitol, fourteen antigens bands of 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KD, were detected. The bands of 100, 72.4, 16.9, 15.5 and 14.9 KDa were been the most reactives. Thereby the SAg, also reduced with dithiothreitol, seven bands of 42.7, 39.8, 34.6, 30.2, 28.0 and 25.2 KDa were detected. They were a bit clear. In conclusion, the E/SAg induce the highest production of immunoglobulin G antibodies in rabbits experimentally immunized.