We present the results of our optical monitoring campaign of the X-ray source H 0507+164 , a low luminosity Seyfert 1.5 galaxy at a redshift , z = 0.018 . Spectroscopic observations were carried out during 22 nights in 2007 , from the 21 of November to the 26 of December . Photometric observations in the R-band for 13 nights were also obtained during the same period . The continuum and broad line fluxes of the galaxy were found to vary during our monitoring period . The R-band differential light curve with respect to a companion star also shows a similar variability . Using cross correlation analysis , we estimated a time delay of \tau _ { cen } = 3.01 ^ { +0.42 } _ { -1.84 } days ( in the rest frame ) , of the response of the broad H _ { \beta } line fluxes to the variations in the optical continuum at 5100 Å . Using this time delay and the width of the H _ { \beta } line , we estimated the radius for the Broad Line Region ( BLR ) of 2.53 ^ { +0.35 } _ { -1.55 } \times 10 ^ { -3 } parsec , and a black hole mass of 9.62 ^ { +0.33 } _ { -3.73 } \times 10 ^ { 6 } M _ { \odot } .