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The purpose of this work was to develop thermal methods to identify the cocrystal systems with stoichiometric diversity.Methods Differential scanning calorimetry (DSC) and hot stage microscopy (HSM) have been applied to study the stoichiometric diversity phenomenon on cocrystal systems of model compound salicylic acid (SA) with different coformers (CCFs).DSC method was particularly useful in the identification of cocrystal re-crystallization,especially to improve the temperature resolution using slower heating rate.HSM was implemented as a complementary protocol to confirm the DSC results.The crystal structures were elucidated by X-ray single crystal diffraction (XRSCD).Results Two new cocrystal systems consist of salicylic acid-benzamide (SA-BZD, 1∶1, 1∶2) and salicylic acid-isonicotinamide (SA-ISN, 1∶1, 2∶1) were identified in the present work.The chemical structures of the newly discovered cocrystals SA-BZD (1∶2) and SA-ISN (2∶1) were elucidated using X-ray single crystal and powder diffraction methods.Conclusions The developed thermal methods could rapidly identify cocrystal systems with stoichiometric diversity, which has potential to discover new pharmaceutical cocrystals in the future.Financial support from the Macao Science and Technology Development Fund (112/2013/A3)and Matching Grant from University of Macau (MRG031/ZY/2015/ICMS) are gratefully acknowledged.