In order to discuss the micromechanism and the simulating method of the curve like coastline. On the basic of the method calculating fractal dimension

and taking the Jiangsu Province coastline as an example

this paper uses the midpoint subdivision interpolation method and the Koch curve method to explore the simulated coastline generation. It puts emphases on the method of Koch curve; introduces its principle of realization and its process of simulation. According to different conditions and needs for simulation

it can not only simulate a section of coastline

calculate its dimension

but also can generate the coastline which dimension is appointed. By this way and with the support of GIS technology

the author designs a utility programmer for simulation based on fractal

and introduces flow of the programmer and analyzes its function in brief. Finally

the coastline of Jiangsu which scale is 1:2000000 is simulated by this program. Finally

some significant conclusions are drawn:(1)the coastline has the fractal character

it's self simulation. (2)the degree of the coastline is direct proportion to the fractal dimension. (3)if the method of simulation is different

the result is also not the same. (4)the technology of GIS is fitting for simulating the coastline.