Air　plasma　has　been　widely　applied　in　industrial　manufacture.　In　this　paper,　both　dry　and　humid　air　plasmas＇　thermodynamic　and　transport　properties　are　calculated　in　temperature　300-100000　K　and　pressure　0.1-100　atm.　To　build　a　more　precise　model　of　real　air　plasma,　over　70　species　are　considered　for　composition.　Two　different　methods,　the　Gibbs　free　energy　minimization　method　and　the　mass　action　law　method,　are　used　to　determinate　the　composition　of　the　air　plasma　in　a　different　temperature　range.　For　the　transport　coefficients,　the　simplified　Chapman-Enskog　method　developed　by　Devoto　has　been　applied　using　the　most　recent　collision　integrals.　It　is　found　that　the　presence　of　CO2　has　almost　no　effect　on　the　properties　of　air　plasma.　The　influence　of　H2O　can　be　ignored　except　in　low　pressure　air　plasma,　in　which　the　saturated　vapor　pressure　is　relatively　high.　The　results　will　serve　as　credible　inputs　for　computational　simulation　of　air　plasma.