Zn0.9Co0.1O　bulks　were　prepared　by　solid　state　reaction　at　various　fritting　temperatures　in　order　to　investigate　the　structural　and　optical　properties　of　the　bulks.　The　valence　electron　and　doping　concentration　in　bulk　was　measured　by　Xray　photoelectron　spectroscopy　(XPS)　instrument.　Some　basic　properties　of　the　bulk　material　in　powder　were　examined　to　enhance　the　comprehension　of　magnetism　in　these　semiconductors.　The　corresponding　magnetic　properties　were　evaluated　by　field-cooling　and　zero-field-cooling　magnetization　measurements,　while　the　optical　properties　were　tested　by　Fourier　transformed　infrared　spectrum　(FTIR).　It　is　indcated　that　Co　ions　are　well　inserted　in　the　ZnO　structure　and　surrounded　by　four　oxygen.　It　means　that　a　series　of　Co　have　substituted　Zn　and　the　sample　all　the　same　maintains　original　wurtzite　structure　in　lattice　with　a　sintered　temperature　of　1200　degrees　C,　then　it　leads　to　chemical　bond　formation　of　Co-O.　Furthermore,　the　fritting　temperature　do　not　play　a　crucial　role　in　the　determination　of　Co　content.