We propose a model of a string which grows at a constant rate and stud
y the characteristic properties of shape transformations. Numerical ca
lculations show that the string grown from a straight line comes to as
sume a complex shape confined in a small region in which we can observ
e a characteristic length. From a statistical point of view, we can sa
y that the string with the complex shape is an assembly of many arcs w
hose mean radius is approximately equal to the characteristic length.
The radius varies, depending on several parameters, but the curvature
histogram can be modified to a unique form by rescaling the length sca
le. This means that all solutions in our model of a growing string are
statistically equivalent. The scaling properties and several other qu
antities which characterize the system are also studied.