In order to obtain the influence of different alkalis on the emulsification and dynamic interfacial tension of heavy oil，the effects of inorganic alkalis including Na₂CO₃，NaOH，NH₃·H₂O and（NH₄）₂CO₃and organic alkalis including CH₃ONa，C₂H₅ONa and C₄H₉ONa on the viscosity of heavy oil and the dynamic interfacial tension between heavy oil and alkali were studied. The results showed that organic alkali had much better emulsifying ability than inorganic alkali. At the same time，organic alkali could avoid the scaling and corrosion caused by inorganic alkali to the pipeline. The influences of organic alkali or inorganic alkali on the dynamic interfacial tension between heavy oil and alkalis were different. The regular patterns of dynamic interfacial tension between heavy oil and inorganic alkalis were different with increasing dosage of inorganic alkalis. The mass fraction of NH₃·H₂O，（NH₄）₂CO₃，Na₂CO₃ and NaOH was 0.8%，1.0%，1.0% and 0.6% respectively，when the minimum interfacial tension reached. The interfacial tension between CH₃ONa or C₄H₉ONa and heavy oil decreased first and then increased with increasing dosage of organic alkali，and the mass fraction of organic alkali was 0.15% when the minimum interfacial tension reached. The interfacial tension between C₂H₅ONa and heavy oil showed a trend of increasing first and then decreasing gradually with increasing dosage of alkali. The organic alkali had an advantage over the inorganic alkali in the emulsification and viscosity reduction of heavy oil and enhancing oil recovery.