It consists of five elements instead of four-Metal, Water, Wood, Fire and Earth. They are agents that subtletly alter the nature of whatever they represent.
Other than these the forces which keep the natural balance of the universe is yin and yang.
There is an interesting aspect behind the naming of the twelve years in the Chinese Lunar cycle and daily Chinese horoscope. Before leaving this world Buddha invited all the animals of this world to a feast. Only twelve animals arrived in a following order- The Rat, the Ox, the tiger, the rabbit, the dragon, the snake, the horse, the sheep, the monkey, the rooster, the dog and the pig.
Thus Buddha decided to name a year after each of them, in order of their arrival. Each year in this twelve year cycle now had a symbolic animal whose characteristics were said to influence the world events, personality and fate of everything and everyone born in that year.
Some scholars say that Chinese horoscope is one of the oldest in the world. However if you trace western astrology back to its Middle Eastern roots both types are likely to have been born in their current recognizable form around 3000 years B.C, however they stem from entirely different beginnings as well as traditions and parts of the world.
The ancient Chinese astronomers called the five major planets by the names of the elements they were associated with: Venus corresponds to metal (gold), Jupiter to Mercury to Water, Mars to Fire, Saturn to Earth. It is said that the position of these planets along with the positions of Sun, moon and any comets in the sky as well as time of birth and zodiac sign can determine a person’s destiny according to Chinese horoscope.
Each of the twelve animals is governed by an element plus a yin-yang direction. Divided into four groups Metal governs monkey, rooster and dog, Wood governs tiger, rabbit and dragon, Water governs pig, rat and Ox, fire governs snake, horse and ram. Additionally there is earth which to some extent governs dragon, dog ram and Ox. It is the central balance of all elements and can lend qualities to all twelve animals as well.
The elements are also associated with colors. The traditional correspondences are green to wood, red to fire, yellow to earth, white to metal and black to water. Some people interpret the years by color and zodiac sign.
There is a common disbelief that there are only single animals assigned for a year. These yearly cycles represent what others perceive you as being. While a person might appear to be a dragon they might actually be a snake internally and ox secretively. Combined with five elements this makes 8640 combinations (five elements, twelve animals, and twelve months, twelve times of day). The inner animal is assigned by the month of birth.
This dictates your love life and inner persona and is critical to proper understanding of your compatibility with other signs. It may be considered what the individual wishes to become, or believes to be their true self. The secret animal is denoted by the exact time of birth and is your own true sign which your personality is based on.
Chinese horoscope refers to a pure cylindrical cycle and is the divination of future from the Chinese calendar.