0-100的是类似收入那种的吧？如果理解没错，可以用medium代替，譬如0-10用5代替

There are assumptions using SEM. But if your variables don't meet them you can use SEM with different estimator like as weighted least squares (WLS). Look at the following link at page 122.

http://psychology.concordia.ca/fac/kline/library/k13a.pdf

Hope it helps