Does good only live in the human heart ?

Good lives in the human heart, but it's also taken from everything around it. A good person can grow up in a bad place, but at the same time, we're only as good as our influences.

In a literal sense, everything you feel, including good, bad, sadness, anger, bitterness, love, envy all are in your brain. Your heart really has nothing to do with it.

well no not just in the human heart
If you have a good heart, then you will help people out, and then the other people will be nice to you.
and you can see the beauty and wonder of the forest, it's god's creation :)
the trees, the rocks, the living organisms(birds) are wonderful things :)
the world is good too, everyone is helping each other
say school help children to educate (education), police for law and order,
the hospital help the sick to be well again.
The society help people by giving them education, giving their a purpose( a job to do).
people help each other to make this world a better place :)
so it's all good :)

Hinduism says that heart is seat of the soul.

http://www.vgweb.org/bsq/bsqtr18.htm

In Homeric times, the heart was considered to be the seat of the soul.

http://www.greekmedicine.net/b_p/Greek_Chakras.html

No. Good can be found in the hearts of non-humans as well. Anyone who has a pet or works with animals will know that.
And good doesn't live in every human heart... You'll find that many human hearts have a complete absence of goodness.

Using the word "heart" to mean human consciousness or whatever is outmoded.... In the past it was felt to have something to do with emotion.....But it's just a pump.

Of more interest is the concept of "good". If you want an answer to your question you need to define "good". Humans have, as part of their nature, the ability to things we classify as good. We are capable of altruism and cooperation and charity and kindness and all those things.
We are as well capable of doing things we refer to as "evil", of being violent and hateful and self-centered and downright nasty.
It's all part of human nature. Now, other animals exhibit such traits as well; they are frequently loving and nurturing and cooperative and protective and all that.
However, we don't normally think of animals as having "volition", of doing these things as a result of conscious decision. Rather, they act instinctually.
So, using the standard of volition, you'd think that only humans were capable of doing "good" things voluntarily.