In order to suit the wide

large guantative and continiously increasing needs of 1: 50

000 survey and mapping of special topics

we use th optical-computer composite processing techniques such as digital interpolation and magnifying

and optimization of band combination

the techniques of making 1:50

000 high quality TM image have been explored. This article introduces the main steps and key techniques of making 1: 50

000 TM image

i.e. （1） magnifying TM CCT data by real times （2.28） using interpolation method; （2） obtaining 1: 250

000 TM latent image through 50 um light-spot scanning on C-4500 Scanner; （3） creating 1:50

000 TM image by optical processing The test studies in Nanpi County

Hebei Province; Mulin County

Heilongjiang Province; Laizhou Bay

Shandong Province have achieved good results.