This work aims to the study of the Sh 2-307 HII region and related stellar population .
Near-infrared imaging and spectroscopic observations in the direction of Sh 2-307 were performed using OSIRIS at SOAR Telescope .
The photometric data were analysed from color-color , and colour-magnitude diagrams , while the spectroscopic results were interpreted from the comparison of the science spectra with that obtained from known OB stars .
From J- , H- and K-band spectra of the brightest source in the cluster , we conclude that it has a near-infrared spectra compatible with that taken for O9 v -O9.5 v stars .
Using the derived spectral type and the respective J , H and K-band photometry , we compute a heliocentric distance of 3.2 \pm 0.5 kpc , which for R _ { 0 } = 8 kpc , puts this cluster at more than 10 kpc from the Galactic centre .
From the Br \gamma , H _ { 2 } , and continuum narrow-band images we were able to detect both the NIR counterpart of the associated HII region , as well as , the interface between the ionised and the cool molecular gas .
Using the 5 Ghz continuum flux density taken from the PMN catalogue and the Br \gamma narrow band image we estimate that the HII region has a mean diameter of 0.94 \pm 0.15 pc , mean electron density of 550 cm ^ { -3 } and an estimated dynamical age of 1.6 \times 10 ^ { 6 } years .
The large fraction of sources presenting excess emission at 2 \mu m suggests that the stellar population is very young , with many sources still in the pre-main sequence accreting phase .
By the use of theoretical pre-main sequence tracks we derived a cluster mean age of about 2.5 Myears , and from the analyses of the fraction of excess emission sources as a function of their spatial distribution we found evidence for an age spread for the embedded pre-main sequence stellar population .
Finally , from the study of the spatial distribution of the low-mass sources relative to the main-cluster source and associated photo-dissociation zones , we conclude that the O-type star probably has been triggering the star formation process in the region .