Thirty genotypes of amaranth (SA01= BARI Data-1, SA02= White data, SA03=Red data, SA004=Lal katua-2, SA05=AM05, SA06=BD8278, SA07=BD8152, SA08=AM51, SA09= AM53, SA10=AM 54, SA11=AM 55, SA12= AM 57, SA13=AM58, SA14=AM61, SA15=AM62, SA16=AM63, SA17= AM64, SA18= AM65, SA19= AM66, SA20= AM67, SA21= AM68, SA22=AM69, SA23= AM71, SA24= AM 72, SA25 = Am 73, SA26 = AM 74, SA27 = AM 75, SA28 = AM 77, SA29 =AM 78 and SA30= AM 79) were studied in a non-replicated trial placed in plastic shed conditions of vegetable research field, HRC, BARI (23.99159 N, 90.41139 E) during 16 July 2017 to 28 August 2017. Ninety pots (height-29 cm, top dia-32 cm and bottom dia-21 cm; capacity 14 L) were used for this experiment. There were three drought treatments- control, 12 days drought and 18 days drought. At first, soil collected from Kodda, Kalikoir Upzilla, Gazipur district, was prepared by cleaning all pieces of bricks, stones and other foreign materials and then soil was air dried. Seven kilogram dried soil was mixed with 4 kg cowdung, 5 g Urea, 6 gm TSP , 6 g MoP, 3 g Gypsum and boric acid (medicate) 1 g for each pot. The ultimate pot capacity was 11.00 kg, when % moisture was 16.9%. Before sowing each pot was irrigated with 2 L water. At the proper moisture condition a little portion of seeds of different genotypes mixed with some fine loose soil was sown in each pot on 16 July 2017. All the genotypes (except SA04, SA05 and SA26) germinated within 5-6 days. The three genotypes SA04, SA05 and SA26 failed to germinate. First thinning was done on 25 July 2017 keeping 10 seedlings/pot. The final thinning was done on 30 July 2018 keeping 6 plants/pot. Pots with all treatments were irrigated every three days up to field capacity (40%) on 06 August 2017. Then the pots with control treatment were kept in well watered condition up to experimentation. After 4 days of irrigation (06 August 2017), 30 pots (actually 27 pots) were kept without water for 12 days which were considered as 12 days drought treatment, and another 30 pots (actually 27 pots) were kept without water for 18 days, which were considered as 18 days drought treatment. The moisture capacity was monitored up to experimentation by Soil Moisture Meter (Model:PMS-714, Taiwan) (Table 1). Each pot was top dressed with 5 g Urea at 10 days interval. Data (from 5 plants) was taken on plant height, number of leaves/plant, chlorophyll content (SPAD value), Fv/Fm value, % relative water content, leaf area/plant, shoot fresh weight/plant, dry weight/plant. The SPAD value was taken by SPAD meter (SPAD-500 plus, Minolta Konica Inc, Japan). The changes in fluorescence yield reflect changes in photochemical efficiency and heat dissipation. The polyphasic rise of fluorescence transients was measured by an ADC Infrared Gas Analysis plant Efficiency Analyzer (PEA, Handsatech Instruments Ltd., King’s Lynn, UK). The initial fluorescence (F0), maximum fluorescence (Fm) were analyzed and quantum efficiency of open photosystem II centres-quantum yield (Fv/ Fm) was calculated. The leaf discs were previously adapted to the dark for 20 minutes. The fluorescence data were collected every day at 10.00 am to 12.00 pm from initial to end of the experiment. Fo is the amount of light absorbed initially to raise the fluorescence from a low level to maximum value Fm after dark adaptation. Fv = Fm-F0 which is the variable. Ratio of Fv/Fm is a dark adapted test used to determine maximum quantum yield. This ratio is also an estimate of the maximum portion of absorbed quanta used in PSII reaction centers. The plants were divided into stems and leaves, dried at 80oC and weighed. Relative water content (RWC) was measured using leaves (4th no. leaf from the tip of the plant) after imposing drought conditions. Immediately after cutting at the base of lamina, leaves were sealed within plastic bags and quickly transferred to the laboratory. Fresh weights were determined within 2 h after excision. Turgid weights were obtained after soaking leaves in distilled water in plastic bowls for 16 to 18 h at room temperature (about 25°C) and under the low light conditions of the laboratory. During soaking bowls are covered with polythene. After soaking, leaves were quickly and carefully blotted dry with tissue paper in preparation for determining turgid weight. Dry weights were obtained after oven drying the leaf samples for 72 h at 70°C.