I had bad erosion with my garden- can I use compost to build it up?

That will not be enough. You will have to build a wall to prevent erosion ,then add amendments to the soil.

thank you very much for your answer.

You should be able to- check out what this article has to say about the benefits of compost against erosion! http://extension.uga.edu/publications/detail.cfm?number=B1200

I lost a lot of dirt. I was wondering about top soil and compost to fix the problem. Flowers would not grow,they lived .

healthy soil with good structure has some resistance to erosion. compost would contribute to the soil's health. but already eroded soil needs more. if you are on a slope, terracing or a retaining wall, done properly, can arrest the erosion. another approach is to add plants that will root deeply to hold the soil.

Thank you