📓 In Haryana, INDIA the first ever diatom data basing was done in ten different water bodies at ten different stations (H1 to H10) and a total 56 genera and 112 species of diatoms were recorded in the year 2008-2009 and 2009-2010, respectively. The major genera identified were Pennales comprises of 49 genera (99 species) and Centrales comprises of 7 genera (13 species). The diatom frequency varied during the change of season. The diatom frequency was low in all the stations during monsoon and maximum during postmonsoon and premonsoon periods.