To　analyze　the　effect　of　the　film　nonlinearity　on　the　quality　of　reconstructed　image　of　electron　tomography　(ET),　the　nonlinear　transform　is　performed　on　the　linear　projection　of　a　model　sample　according　to　a　D-lgE　characteristic　curve　of　the　film,　whose　parameters　are　taken　from　the　Kodak　4463　(SO163)　film,　and　the　3D　reconstruction　is　worked　out　by　computer　simulation.　The　simulation　results　show　that　the　quality　of　the　reconstructed　image　decreases　with　the　increase　of　the　nonlinearity　of　the　part　of　the　D-lgE　curve,　which　corresponds　to　the　maximum　exposure　range.　Especially,　when　the　maximum　exposure　range　extends　to　the　saturation　region　of　D-lgE　curve,　the　reconstructed　image　appears　to　be　distorted　seriously　and　the　correlation　factor　between　the　reconstructed　image　and　the　model　sample　may　drop　from　0.85,　which　corresponds　to　linear　projection　series,　to　a　value　below　0.6.　It　is　also　indicated　that　adjusting　the　electron　exposure　on　the　film,　i.e.　changing　the　position　of　the　maximum　exposure　range　on　the　D-lgE　curve,　can　reduce　the　nonlinear　effect　of　the　film　on　3D　reconstructed　image.　This　result　is　useful　for　ET　when　the　film　is　used　to　record　image　data.