Typically, people are most drawn to people of signs that are either of the same element or of the opposite element. There are twelve signs in the solar zodiac. They are grouped together to correspond to the four elements of earth, water, fire and air.
The three earth signs are Capricorn, Virgo and Taurus. The three water signs are Cancer, Scorpio and Pisces. Since earth and water are opposite signs, people who are Scorpios, for instance, may potentially find themselves attracted to people of the Capricorn, Virgo, Taurus, Cancer or Pisces signs. Likewise, the three fire signs are Aries, Sagittarius, and Leo. The three air signs are Libra, Aquarius and Gemini. Since fire and air are opposites in the zodiac, people of belonging to any of those six signs could feel drawn to each other.
The Chinese zodiac, which is a lunar base astrological chart, does not use elements determined by months to determine compatibility, but animals determined by years. Like the solar zodiac, there are twelve signs of the Chinese zodiac that are grouped together in groups of four according to compatibility. The twelve signs are rat, ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, rooster, dog and pig.
Unlike in the solar zodiac, however, just because one sign is grouped with others to which it may be naturally attracted, that does not mean that all of the signs in that group will feel mutually drawn to each other. Rat is attracted to ox, rabbit and dragon, for instance. While rabbit is mutually drawn to rat, it does not feel an equal appeal to dragon.