Ned's build was strong and tall compared to his own shorter, wiry one.
两个人的体格比较，这原句的compared可以改用comparing吗？要如何理解文法，何时用-ed 与何时用-ing 呢?

体格不会主动比较，是被拿来比较

不行，compared这里算被动，Ned’s build was tall (when) compared (by some observers) to his.Comparing Ned’s tall build to his own, his was shorter.前面comparing例子是He compares Ned’s build to hisown,是主动。

终于弄懂了，不懂好久，感谢解惑

上面(by some observers)是(by himself)才对，打错