Abstract: The growth of the green alga Haematococcus pluvialis in vegetative stage is one of the most important parts in the whole cultivation process. The aim of the study was to show the growth characteristics of the alga under 100 and 170 μmol photon m-2 s-1 light intensities in the longer Light Path (LP) lengths (17.5, 23.0 and 27.5 cm) than the ones usually used. Maximum cell numbers increased from 15.7, 11.5 and 10.1 x 104 cells mL-1 in 100 μmol light to 17.9, 12.9 and 11.1 x 104 cells mL-1 under 170 μmol light for 17.5, 23.0 and 27.5 cm LP lengths, respectively. The cell concentration per liter volume increased as in the pattern of cell count. The Chl/Car ratio in the whole groups, a very useful indicator to evaluate the stress on the cells, increased by the shift of light from 100 to 170 μmol. The close correlation between cell number and absorbance value at 680 nm (p<0.04) showed the biomass concentration to depend on the cell count rather than DW and cell diameter. In addition, cell diameter did not change during the experiments. As a result of the findings, the use of longer LP lengths may be an alternative method in the vegetative cultivation of the light sensitive alga Haematococcus pluvialis by the higher light intensities than 200 μmol photon m-2 s-1 using mutual shading effect.