The plant drought tolerance is one of the important parameters for selecting sustainable landscape plants. In this paper Trifolium repens Cultivars, ‘Haifa’ and ‘Rivendel’, were studied for their photosynthesis and root spatial distribution under different drought stresses. These two varities were grown separately in the 15cm diam, 60cm deep pots, and irrigated for 81d. Pots were then either irrigated or subjected to water deficit (CK: no water stress; LS: the up 20 cm soil was under the state of drought; HS: the up 20 cm soil was under the state of extreme drought, and the 20-40 cm soil was under the state of drought). The results showed that there were no differences in plant photosynthesis or root growth between the two cultivars under adequate water supply. Net photosynthetic rates and water use efficiency increased, and the root growth was enhanced for ‘Haifa’ with moderate water stress in the 0-20 cm soil layer, but there was no significant change for ‘Rivendel’. Under extreme drought condition in 0-20 cm soil, and drought condition in 20-40 cm soil, the cultivar ‘Haifa’ was affected only slightly at the first stage of the experiment and later recovered to a normal state, while ‘Rivendel’ was much more adversely effected. Degree and time of the moisture stress increased the root/shoot ratios gradually for plants of ‘Rivendel’. Compared to ‘Rivendel’, the root/shoot ratio for ‘Haifa’ did not increase significantly given the same experiment conditions as ‘Haifa’, but there were more deeper roots for ‘Haifa’ than for ‘Rivendel’. Therefore, it is believed that ‘Haifa’ was more drought resistant than ‘Rivendel’.