We present the result of radio observations of red supergiants in the star cluster , Stephenson ’ s # 2 , and candidates for red supergiants in the star clusters , \citet mer05 ’ s # 4 , # 8 , and # 13 , in the SiO and H _ { 2 } O maser lines . The Stephenson ’ s # 2 cluster and nearby aggregation at the South-West contain more than 15 red supergiants . We detected one at the center of Stephenson ’ s # 2 and three in the south-west aggregation in the SiO maser line , and three of these 4 were also detected in the H _ { 2 } O maser line . The average radial velocity of the 4 detected objects is 96 km s ^ { -1 } , giving a kinematic distance of 5.5 kpc , which locates this cluster near the base of the Scutum-Crux spiral arm . We also detected 6 SiO emitting objects associated with the other star clusters . In addition , mapping observations in the CO J = 1 –0 line toward these clusters revealed that an appreciable amount of molecular gas still remains around Stephenson ’ s # 2 cluster in contrast to the prototypical red-supergiant cluster , Bica et al. ’ s # 122 . It indicates that a time scale of gas expulsion differs considerably in individual clusters .