This article has studied fruit growth rhythm of the processing tomato, and offered the scientific basis for developing the yield and quality of the fruit in the practical production. Taking Legel87-5 and Xinyin98-1 as the material, the changes rule of the fruit vertical, the transverse diameter and fresh weight were studied. The results showed that two varieties’ growth dynamic assumes "quick - slow - quick" "S" curve, and the entire development period may be divided into 3 stages approximately--first fast growth period, slow growth period and second fast growth period. Among of the above, second fast growth stage showed obvious growth, two varieties have achieved above 50% of growth in the stage. .
