1. The invention discloses an abortus Brucella vaccine recombinant strain and an application thereof in preparing vaccine.

2. The invention discloses an abortus Brucella vaccine strain S19 marked recombinant strain and an application thereof.

3. The invention discloses brucella abortus immune marking recombinant strain and the application thereof in preparation of vaccine.

4. A fetus of 20 weeks gestation or a fetus weighing 500 gm is considered abortus.

5. The recombinant strain is a strain obtained by deactivating capsular polysaccharide synthesis protein gene and carboxyl uridine phosphate decarboxylase gene in the abortus Brucella strain S19.