Can I specific font-family that use to generate apidocs while I use command mvn site.
You can specify a custom stylesheet file in your maven plugin configuration.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.10</version>
<configuration>
<stylesheetfile>${basedir}/path/to/your/stylesheetfile.css</stylesheetfile>
...
</configuration>
</plugin>