Java EE (Java Enterprise Edition) General Discussion

When i try to start the Tomcat5.5 it pops up a new command prompt but it generates some exceptions. Any idea what i am doing wrong here?
C:\TomCat\apache-tomcat-5.5.16\bin>shutdown
Using CATALINA_BASE: C:\TomCat\apache-tomcat-5.5.16
Using CATALINA_HOME: C:\TomCat\apache-tomcat-5.5.16
Using CATALINA_TMPDIR: C:\TomCat\apache-tomcat-5.5.16\temp
Using JRE_HOME: C:\jdk1.3
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/ap
talina/startup/Bootstrap (Unsupported major.minor version 48.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:486)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.
1)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:248)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:297)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:286)
at java.lang.ClassLoader.loadClass(ClassLoader.java:253)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313)

thank you in advance