how to caculate when zener diode is different direction

it's current different?

 

Hello,

I moved it to the homework section, as it looks like a homework question.

Take a look at this page for the zener diode characteristic:
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/zener.html

You can see the zener effect goes one way and the other way it acts as a normal diode.
Now you can calculate the currents.

Bertus

 

A zener is a modified silicon diode, it looks just like a diode when conducting. When back biased it looks just like a conventional diode until the break over voltage (or zener) voltage is reached, then it is a primitive voltage regulator.