iMovie can support some MPG files. But these kinds of .mpg (multiplexed MPEG1 or MPEG2) are exception. Anyway, it can support some HD file format like AVCHD camcorder shootings. One of its outstanding feature is intuitive-to-operate, it makes it popular among Mac users. In order to edit MPG in iMovie, I would like to advise you to try a third-party software, which can convert MPG to iMovie compatible file formats like MOV, MP4, DV, etc.

Doremisoft MPG to iMovie Converter is the right software. Compared with iMovie, it can be much easier to use. It can do the mpg or mpeg to iMovie DV, MOV, MP4, etc with fantastic video quality. Anyway, it provides some useful editing options, even you can do the video trimming or cropping without iMovie.

Now, let's have a look at how to convert MPEG to iMovie on Mac Lion OSX:

1. Free download the MPEG to iMovie Converter
2. Add mpg videosClick "Add File" to import .mpg videos. Plus, it can accept almost all video and audio files can be imported. The batch mode supports a batch files can be load at one time.

3. Choose iMovie as output

4. Convert mpg videosHit "START" button. Then the conversion will be launched.

5. Import MPG to iMovieFirst start iMovie, then choose File>Import, next, choose the converted videos you want to import .mov or .dv file(s) from your project library, finally click Open to import.