It is a long-standing question how high-mass stars are formed in galaxies. Recently, cloud-cloud collisions have received much attention as a mechanism for the formation of high-mass stars and clusters. We report the first evidence of high-mass cluster formation triggered by collisions of molecular clouds in M33. Using the Atacama Large Millimeter/submillimeter Array (ALMA), we spatially resolved filamentary structures of the giant molecular cloud (GMC) 37 in M33 with <sup>12</sup>CO(<i>J</i> = 2-1), <sup>13</sup>CO(<i>J</i> = 2-1), and C<sup>18</sup>O(<i>J</i> = 2-1) line emission at a spatial resolution of ~2 pc. We find two individual clouds with a systematic velocity difference of ~6 km s<sup>-1</sup>. Three continuum sources consisting of up to ~10 high-mass stars are embedded within the densest parts of the molecular clouds which are bright in C<sup>18</sup>O(<i>J</i> = 2-1) line emission. The two molecular clouds show a complementary morphology with a spatial displacement of ~3.5 pc, and show a V-shaped structure in the position-velocity diagram. We also note that the systemic velocity difference between the two clouds cannot be explained by stellar feedback from the high-mass stars. These observational features traced by CO and its isotopes are consistent with those in high-mass star-forming regions created by cloud-cloud collisions in the Milky Way and the Magellanic Clouds. In this poster, we will discuss the formation mechanism of the high-mass star cluster in the GMC 37 in M33.