The airborne systems complied with the ARINC661 standard are called the A661 member system. The software for the system is referred to the A661 airborne software in the research. Theoretically,some critical technology of the A661 airborne software are analyzed in this paper and the research results have been utilized for the advanced civil aircraft in practice. The airborne systems complied with the ARINC 661 standard are called the A661 member system. The software for the system is referred to the A661 airborne software in the research. Theoretically, some critical technology of the A661 airborne software are analyzed in this paper and the research results have been utilized for the advanced civil aircraft in practice.