if theory permits you,  look at the modification indices (View--> Analysis Properties---> Output--> Modification indices) and do according them. Otherwise stay with these results and try to explain according to the model theory.

能更详细一些吗？如何根据修正指标解释？还是根据修正指标修正模型后，再看这些拟合指标的情况吗？

From Amos help"Amos computes a modification index for each parameter that is fixed at a constant value and for each parameter that is required to equal some
other parameter. The modification index for a parameter is an estimate of the amount by which the discrepancy function would decrease if the
analysis were repeated with the constraints on that parameter removed. The actual decrease that would occur may be much greater.
Amos computes modification indices not only for parameters that are explicitly constrained, but also for parameters that are implicitly assumed
to be zero. For example, a modification index is computed for every covariance that is fixed at zero by default".
Furthermore the following link:
http://core.ecu.edu/psyc/wuenschk/MV/SEM/CFA-AMOS.doc
and a very helpful video in youtube
http://www.youtube.com/watch?v=vM5nHV-0__w
I hope that i helped you.

欧拉，问题解决了，谢谢楼上的热心帮助

mofidacation index 怎么改的啊