diff --git a/src/Eth.php b/src/Eth.php
index 44e237b..898156e 100644
--- a/src/Eth.php
+++ b/src/Eth.php
@@ -6,6 +6,8 @@ use Web3\Providers\Provider;
 use Web3\Providers\HttpProvider;
 use Web3\RequestManagers\RequestManager;
 use Web3\RequestManagers\HttpRequestManager;
+use Web3\Validators\AddressValidator;
+use Web3\Validators\TagValidator;
 
 class Eth
 {
@@ -30,6 +32,12 @@ class Eth
         'eth_gasPrice' => [],
         'eth_accounts' => [],
         'eth_blockNumber' => [],
+        'eth_getBalance' => [
+            'params'=> [
+                AddressValidator::class,
+                TagValidator::class
+            ]
+        ],
     ];
 
     /**
diff --git a/src/Validators/AddressValidator.php b/src/Validators/AddressValidator.php
new file mode 100644
index 0000000..22ec3e5
--- /dev/null
+++ b/src/Validators/AddressValidator.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Web3\Validators;
+
+use Web3\Validators\IValidator;
+
+class AddressValidator
+{
+    /**
+     * validate
+     *
+     * @param string $value
+     * @return bool
+     */
+    public static function validate($value)
+    {
+        if (!is_string($value)) {
+            return false;
+        }
+        return (preg_match('/^0x[a-fA-F0-9]{40}$/', $value) >= 1);
+    }
+}
\ No newline at end of file
diff --git a/src/Validators/TagValidator.php b/src/Validators/TagValidator.php
new file mode 100644
index 0000000..62850d5
--- /dev/null
+++ b/src/Validators/TagValidator.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Web3\Validators;
+
+use Web3\Validators\IValidator;
+
+class TagValidator
+{
+    /**
+     * validate
+     *
+     * @param string $value
+     * @return bool
+     */
+    public static function validate($value)
+    {
+        $tags = [
+            'latest', 'earliest', 'pending'
+        ];
+
+        // maybe change in_int future
+        return (is_int($value) || in_array($value, $tags));
+    }
+}
\ No newline at end of file
diff --git a/test/unit/EthTest.php b/test/unit/EthTest.php
index c221b41..7d5e44e 100644
--- a/test/unit/EthTest.php
+++ b/test/unit/EthTest.php
@@ -199,6 +199,27 @@ class EthTest extends TestCase
         });
     }
 
+    /**
+     * testGetBalance
+     * 
+     * @return void
+     */    
+    public function testGetBalance()
+    {
+        $eth = $this->web3->eth;
+
+        $eth->getBalance('0x407d73d8a49eeb85d32cf465507dd71d507100c1', 'latest', function ($err, $balance) {
+            if ($err !== null) {
+                return $this->fail($err->getMessage());
+            }
+            if (isset($balance->result)) {
+                $this->assertTrue(is_string($balance->result));
+            } else {
+                $this->fail($balance->error->message);
+            }
+        });
+    }
+
     /**
      * testUnallowedMethod
      *