An　algorithm　to　construct　the　generator　of　gauge　transformation　for　a　system　with　singular　higher-order　Lagranian　in　field　theories　is　given.　Starting　from　generating　functional　of　Green　function　in　phase　space,　the　Ward　identities　in　canonical　formalism　for　the　constrained　Hamiltonian　system　are　deduced.　It　is　pointed　out　that　the　quantal　canonical　equation　for　such　a　system　deffers　from　the　classical　canonical　equation,　arising　from　the　fact　that　Dirac　conjecture　is　valid.　The　quantization　for　a　generalized　dynamical　system　which　can　be　equivalent　to　Chern-Simons　theory　is　given.　With　preliminary　application　of　canonical　Ward　identities　to　such　a　system,　some　relationships　among　the　vertices　and　propagators　for　the　fields　can　be　deduced　without　carrying　out　the　integration　for　canonical　momenta　in　phase　space　path　integral.