The　effects　of　La/Sn　co-substitution　at　A　and　B　sites　of　Ba4Nd2Ti4Ta6O30　ceramics　were　investigated.　With　La/Sn　co-substitution,　the　temperature　coefficient　was　significantly　improved　to　near　zero,　at　the　same　time,　dielectric　constant　reduced　and　dielectric　loss　increased.　In　particular,　remarkable　annealing　effects　on　dielectric　properties　were　observed　for　these　modified　ceramics.　After　annealing,　dielectric　constant　considerably　increased,　and　temperature　coefficient　shifted　to　more　negative.　(C)　2005　Springer　Science　+　Business　Media,　Inc.