Abstract: Applied with test of potted plant and measurement absorbency for study response of the contents of photosynthetic pigments of slash pine’s half-sib under water stress. There are 7 families comparison with general slash pine(ab. CK). The contents of photosynthetic pigments are mensurated under feebleness water stress while soil water content is 55% to 60% and moderate water stress while soil water content is 35% to 40% and heavy water stress while soil water content is 20% to 25%. The test result indicate that either water grads or families of chlorophyll (Chl) and chlorophyll a (Chla) and chlorophyll b (Chlb) and Chla/Chlb and carotenoid (Caro) and Caro/Chl are mighty notable difference. The Chl and Chla and Chlb and Chla/Chlb little drop from normal soil water to initial water stress. Then drop obvious with increased water stress. The Caro and Caro/Chl little drop firstly from normal soil water to initial water stress,then up in metaphase water stress,after drop in evening water stress. The Chl and Chla and Chlb and Chla/Chlb and Caro of slash pine’half-sib are over general slash pine. The Chl and Chla and Chlb and Chla/Chlb and Caro of 464 and 1027 are over average value of slash pine’s half-sib under water stress. The Caro/Chl of 609 and 46 are over average value of slash pine’s half-sib under water stress. There are high contents of 464 and 1027 under water stress. It is one of the physiology reason with growth fast and high yield of 464 and 1027