The yttrium(Y)-modified) gamma-Al2O3 was used as support for trimetallic PtSnIn catalysts (PtSnIn/xY-Al) and applied in propane dehydrogenation reaction. The PtSnIn/xY-Al catalysts were characterized by several state-of-art techniques such as XRD, BET, NH3-TPD, TEM, H-2-TPR, and XPS measurements. The results show that the catalytic performances of PtSnIn/xY-Al catalysts for propane dehydrogenation reaction are clearly improved. The NH3-TPD curves demonstrate that Y-modified gamma-Al2O3 could greatly weaken the acidity of the support. The PtSnIn/0.6Y-Al catalyst has the smallest Pt particle size of 16 nm and homogenized particle distribution. XPS and H-2-TPR techniques verify that the loading of Y influences the state of metals and its interactions with support. In this study, the initial propane conversion and propylene selectivity attain above 50% and 97% for PtSnIn/0.6Y-Al catalyst, respectively. However, with excessive Y loading, the agglomerations of Pt particles and more metallic (Sn-0) are found, which leads,to the loss of catalytic activity. (C) 2016 Elsevier B.V. All rights reserved.