Now, only Con Dao island in Vietnam have been had sea turtles mainly species of Green turtles (Chelonia mydas) breeding grounds on the beach per year, the number of Green turtles mother about 350 individuals account for more than 80 percent of Green turtles breeding in Vietnam. The time of Green turtles breed usually begin in March and end in December, concentration on the June to September and on average accounted for 83.12 percent of the laying per year, The size of Green turtles in Con Dao native smaller are CCl = 96.50 percent +/- 5.73 (cm). CCW = 86.30 percent +/- 5.54 (cm). number eggs per nest: 90.2 percent 14.92 (eggs). The eggs size and weight of Green turtles in Con Dao: DAv = 41.57 percent +/- 1.41 (mm) WE = 38.76 percent +/- 3.74 (g). Size and weight are correlated very closely upon and according to the equation: DAV = 2.5852 DAv-68.709 (R = 0.97 for n = 400). Size and weight before the newly hatched Green turtles: SCW = 38.05 percent +/- 1.49 (mm)
SCl = 46,38 percent +/- 1,75 (mm)
WH = 20.69 percent +/- 1.86 (g)
Speed of the Green turtle on the sand = 0.3 percent 0.07 (m/s), size and weight of the Green turtles in Con Dao has not difference compared to the other population Green turtles in the world, the shells area (S) with the weight of Green turtles (WH) have a low correlation in the regression equation: WH = -1.22+0.0124.S-1.2172 with R = 0.8
n = 334. Average of hatching rate is 77.7 percent +/- 13.2 percent, hatching rate of nests in the beach is higher more than in the tank above. The T = 56.83 percent 3.19 days is the time from the Green turtle breeding until the baby Green turtle running on the sand, that time is longer more than the time of Green turtles population in some areas in the world. The knowledge is these bio-indicators is important for the recovery of Sea turtle conservation in Con Dao in particular and Vietnam in general.