I did a search and found there were couple of threads talked about this.However,I saw the picture they posted,the surface will show silverish color if there's a chip presents.Mine is on the front driver fender and it's like a black dot.I was thinking that it's just dirt at the beginning,after trying wiping I found out that it's a chip The car only got 800km on it and how could it be?
Ok,how come it shows black instead of silver? Cauz it's plastic? I am really upset now.

 

Get used to it. There's lots of them...

 

Could be primer, could be slightly oxidized primer, could be oxidized metal... it all depends how deep the chip is.

Wait until spring, read a bit about touch-up procedures in the meantime, and when the weather is nice, use your newfound knowledge to fix the chip.

This is a yearly process for me it seems.

 

the fender close to the tire I think it would be plastic,no? Hope it's plastic,then I could worry less since it won't cause rust later on.
Yeah,ottawa area is harsh in winter............

 

Are you talking about inside the wheel-well? If so, then yes that area is plastic.

I'm pretty sure the exterior fender (where the paint is) is sheetmetal. Tap it with your fingernail... if it sounds metallic, you have your answer. Or, grab a kitchen magnet and check.