The　mutual　diffusion　coefficients　of　ethanol　+　n-heptane　and　diethyl　carbonate　(DEC)　+　n-heptane　binary　solutions　were　measured　over　the　mass　fraction　from　0.05　to　0.95　at　the　pressure　of　0.101　MPa,　and　at　temperatures　T　=　288.15　K,　298.15　K,　308.15　K　and　318.15　K.　The　expanded　relative　uncertainty　(k　=　2)　of　the　Mach-Zehnder　digital　holographic　interferometry　employed　in　the　measurements　was　estimated　to　be　less　than　2.4%　with　the　confidence　level　of　0.95.　A　semi-empirical　correlation　was　used　to　fit　the　mutual　diffusion　coefficients　as　a　function　of　concentration　and　temperature,　which　represents　the　experimental　values　with　the　absolute　average　relative　deviations　being　0.94%　for　ethanol　+　n-heptane　and　0.90%　for　DEC　+　n-heptane.　The　temperature　and　concentration　dependences　of　the　mutual　diffusion　coefficients　were　investigated.　The　strongest　non-ideal　thermodynamic　behaviors　appear　when　the　mass　fraction　of　ethanol　is　within　the　limits　of　0.45　to　0.65　or　that　of　DEC　is　within　the　limits　of　0.45　to　0.65.　Besides,　the　mutual　diffusion　coefficients　of　ethanol　+　n-heptane　and　DEC　+　n-heptane　binary　solutions　are　found　to　be　extremely　sensitive　to　the　solute　concentration　over　the　mass　fraction　of　ethanol　and　DEC　from　0.00　to　0.05,　respectively.　(C)　2020　Elsevier　Ltd.