Abstract: The study was focused on the comparison of protective efficacy between two recombinant subunit vaccines against serotype 1 and serotype 2 of Actinobacillus pleuropneumoniae in mice, with one containing recombinant ApxⅠ , ApxⅡ , ApxⅢ and OMP(named Trial group Ⅰ) and the other containing recombinant ApxⅠ, ApxⅡ, ApxⅢ , ApxⅣ, OMP and Apfa(named Trial group Ⅱ). The BALB/c mice were vaccinated at days 0 , 14 and 28 subcutaneously, and then challenged with serotype 1 strain Shope 4074 and serotype 2 strain 1 536 intranasally at day 35 The protective efficacy was evaluated in terms of mortality, lung lesions, bacterial distribution of lung, then the relationship was evaluated between antibody level and protective efficacy. The results suggested that Trial group Ⅰ had a significantly higher antibody level against ApxI, ApxⅡ, ApxⅢ and OMP than that of other two groups (P<0.05). The protective efficacy against serotype 1 of Trial group Ⅰ （9/10） was obviously higher than that of Trial group Ⅱ （5/10）and Control group （0/8）, and the protective efficacy against serotype 2 of that (no lung lesion) was obviously better than others( typical lung lesion).The bacterial clearance of lung in Trial group Ⅰ was efficacious than the other two groups. It was demonstrated that antibody level had a positive correlation to protective efficacy. So,Trial group Ⅰ could provide better crossing protection, which will provide a reference for the development of new vaccine.