The Hygrophila Spinosa T. Anders (HST) plant seed that contains mineral constituents were doped in SnO2 prepared by the conventional method. The structural parameters, functional groups, surface morphology, elemental analysis and optical behavior of the prepared samples was made using X-ray diffraction, Fourier transform-infra red, scanning electron microscope, energy dispersive X-ray analysis, diffuse reflectance spectroscopy techniques respectively have been studied. XRD-surface area for all the samples was obtained from the Williamson-Hall plot. Photoconductivity studies were carried out for all the samples prepared with different HST composition in SnO2. The negative photoconductivity was observed for the HST doped SnO2 and HS samples, except pristine SnO2. The SH2 sample with high specific surface area shows good response and recovery characteristics toward humidity. © 2015 Elsevier Ltd. All rights reserved.