The　basic　concepts　about　the　active　structures　and　some　attributes　of　the　modes　were　presented　in　paper　Liner　Active　Structures　and　Modes　(I).　The　characteristics　of　the　active　discrete　systems　and　active　beams　were　discussed,　especially,　the　stability　of　the　active　structures　and　the　orthogonality　of　the　eigenvectors.　The　notes　about　modes　were　portrayed　by　a　model　of　a　seven-storeyed　building　with　sensors　and　actuators.　The　concept　of　the　adjoint　active　structure　was　extended　from　the　discrete　systems　to　the　beams　which　were　the　representations　of　the　continuous　structures.　The　two　types　of　beams　with　different　placements　of　the　measuring　and　actuating　systems　were　discussed　in　detail.　One　is　the　beam　with　the　discrete　sensors　and　actuators,　and　the　other　is　the　beam　with　the　distributed　sensor　and　actuator　function.　The　orthogonality　conditions　were　derived　with　the　modal　shapes　of　the　active　beam　and　its　adjoint　active　beam.　An　example　shows　that　the　variation　of　eigenvalues　with　feedback　amplitude　is　suitable　for　the　homo-configuration　and　non-homo-configuration　active　structures.