A Java utility application that can convert data in the CSSCI format to the WoS format is available for download at the following link:
http://cluster.ischool.drexel.edu/~cchen/citespace/utilities/CSSCIREC(new).jar
Store data files downloaded from CSSCI to a folder. Before using the format converter, make sure that the input data files with the ANSI encoding are saved to files with the UTF-8 encoding (Use any text editor and then Save As to files with the UTF-8 encoding). Then apply the converter to the data folder.
In order to use data files with Chinese encoding, use Preferences ►Chinese Encoding.
For more discussions in Chinese, see the following links:
http://blog.sciencenet.cn/blog-496649-427780.html
See examples provided by Jie LI (李杰), example #4:
http://blog.sciencenet.cn/blog-496649-838067.html
Once you downloaded the records from CSSCI, switch to CiteSpace > Data>Import/Export>CSSCI. Use the Browse buttons to locate the input and output directories, where your downloaded CSSCI data files should be saved in the input directory. Then press the Format Conversion button.