Molecular clouds associated with compact HII regions in Galactic plane

13CO (J = 1 − 0) emission of massive star forming region including 15 ultracompact and 4 compact HII regions in Galactic plane was mapped with the 13.7 m millimeter wave telescope of Purple Mountain Observatory. The present observations provide the first complete structure of the clouds in 13CO with a higher spatial resolution and a wide-field coverage of 28′ x 45′. Combined with the images of far-infrared emission and dust color temperature obtained from ISSA, various possible dynarnical connections between the compact HII regions and associated clouds were found. We presente some reasons to explain the formation of new dense cold core and molecular emission cavity in the massive star formation and early evolution. The luminosities of excitation stars for all HI1 regions and the main parameters of associated clouds are also derived. The results show that the newborn stars’ luminosities are correlated with the13CO column densities, masses (in 55″beam) and 13CO velocity widths obviously.