installing certificate in key chain

my private key chain dose not showing the certifi开发者_运维知识库cate that i have recently downloaded. on double clicking the certificate and assigning the key chain doesnot showing the certificate in drop down menu!

I would check:

• If the certificate has not expired.
• If you have installed the root certificate this one refers to.

1. Check in Login keychain or other accounts whether you certificates exists in that or not. or

2. Make sure you have clicked All Items in the Category Section on the Left bottom side