使用参数GUESSINGROWS=。如楼上所说默认GUESSINGROWS=20，只用前20行判断。改成大数字就可以了。最大可以32767。

The proc import  uses first (n=20??  not sure) rows to determine all data set attributes. It can be dangerous.

Save the file in a tab delimiter format and read it in as a text file as you wish (=define all attributes yourself).