The Zhangwu-Heishan area is located to the east of the Fuxin-Yixian Basin and is mostly covered with volcanic rock. At various periods, different geologists had varying opinions about their age and periods of volcanic eruptions, especially on sequences between volcanic rock and main coal-bearing strata, which affect the direction of searching for coal, as well as prospecting the entire research area. During our study, we carried out detailed field investigations in this research area; observed and recorded the main repre- sentative outcrops of volcanic rock. We collected over 20 volcanic rock samples and tested the Sensitive High Resolution Ion Microprobe II (SHRIMP II) U-Pb isotope age of 11 samples. The age of our volcanic rock samples ranged between 56.0 ± 2.9 and 132.3 ± 2.3 Ma. After taking earlier investigations into con- sideration, we concluded that, except for a suite of paleogene olivine basalt, the volcanic rock in the Zhangwu-Heishan area is younger than the coal-bearing Shahai Formation. It is therefore most unlikely to find coal seams equivalent to those of the early Cretaceous Shahai Formation in Fuxin Basin below vol- canic rock. At various periods, different geologists had diverse opinions about their age and periods of volcanic eruptions, especially on sequences between volcanic rock and main coal-bearing strata, which affect the direction of searching for coal, as well as prospecting the entire research area. During our study, we carried out a detailed field investigations in this research area; observed and recorded the main repre- sentative outcrops of volcanic rock . We collected over 20 volcanic rock samples and tested the Sensitive High Resolution Ion Microprobe II (SHRIMP II) U-Pb isotope age of 11 samples. The age of our volcanic rock samples ranged between 56.0 ± 2.9 and 132.3 ± 2.3 Ma. After taking earlier investigations into con- sideration, we said that, except for a suite of paleogene olivine basalt, the volcanic rock in the Zhangwu-Heishan area is younger than the coal-bearing Shahai Formation. It is therefore most unlikely to find coal seams equivalent to those of the early Cretaceous Shahai Formation in Fuxin Basin below vol- canic rock.