Php – How to install php56 on CentOS 6 x86_64

When I run yum install php php-devel php-mysql php-gd php-mbstring, it will install php5.3.

yum list installed *php*
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
 * base: ftp.tsukuba.wide.ad.jp
 * epel: ftp.kddilabs.jp
 * extras: ftp.tsukuba.wide.ad.jp
 * updates: ftp.tsukuba.wide.ad.jp
Installed Packages
php.x86_64                       5.3.3-46.el6_6               @updates
php-cli.x86_64                   5.3.3-46.el6_6               @updates
php-common.x86_64                5.3.3-46.el6_6               @updates
php-devel.x86_64                 5.3.3-46.el6_6               @updates
php-gd.x86_64                    5.3.3-46.el6_6               @updates
php-mbstring.x86_64              5.3.3-46.el6_6               @updates
php-mysql.x86_64                 5.3.3-46.el6_6               @updates
php-pdo.x86_64                   5.3.3-46.el6_6               @updates

I just removed it yum remove php php-cli php-common php-devel php-gd php-mbstring php-mysql php-pdo.

And I tried yum install php56w php56w-devel php56w-mysql php56w-gd php56w-mbstring, but they are not available.

Loaded plugins: fastestmirror, security
Setting up Install Process
Loading mirror speeds from cached hostfile
 * base: ftp.tsukuba.wide.ad.jp
 * epel: ftp.kddilabs.jp
 * extras: ftp.tsukuba.wide.ad.jp
 * updates: ftp.tsukuba.wide.ad.jp
No package php56w available.
No package php56w-devel available.
No package php56w-mysql available.
No package php56w-gd available.
No package php56w-mbstring available.
Error: Nothing to do

How can I install php5.6 on CentOS 6?