So your Sun zodiac sign is Leo and you cannot love Scorpios, or Gemini and Pisceans are your problem. There certainly seems to be a case for the belief that certain combinations of Sun signs are difficult whereas others are easy when it comes to whom you love. Sign compatibility based on Sun sign alone, however, is a recent emphasis arising out of disregard of the astrological tradition. Before we look at this, let's see which signs are likely to be compatible and which not.
Whichever element your Sun is in, then, other things being equal (which often they are not!), people with the Sun in other signs of the same element are likely have good compatibility with you. The elements are:
Fire: Aries, Leo, Sagittarius
Earth: Taurus, Virgo, Capricorn
Air: Gemini, Libra, Aquarius
Water: Cancer, Scorpio, Pisces
Next, you are likely to have almost as good compatibility with people with
the Sun in the other element of the same polarity. The polarities are:
Positive: Fire and Air
Negative: Earth and Water
An exception to this is that there may be tension with people with the Sun
in the sign opposite yours in the zodiac. The signs opposing each other are:
Aries - Libra
Taurus - Scorpio
Gemini - Sagittarius
Cancer - Capricorn
Leo - Aquarius
Virgo - Pisces
But note that opposites have a habit of being attracted to one another! The
tension can be fruitful and lead to greater awareness in the partners involved.
Other combinations are liable to be stressful in varying degrees, again, other things being equal (which, again, often they are not). These combinations are:
Fire with Earth or Water
Earth with Fire or Air
Air with Earth or Water
Water with Fire or Air
Again, do not be put off from engaging in such combinations. They can work
very well. I have noticed that a particularly fruitful combination is where
your partner has the Sun in the same element as you and Venus in the psychologically
opposite element. For instance if you have Sun in Gemini and Venus in Taurus,
then you might attract Sun in Aquarius and Venus in Sagittarius.
It is easy to see how the emphasis on Sun sign compatibility came about. We now know the Sun to be the centre of the solar system, so it is natural to see the Sun in birth charts as representing the centre of the person. So the position of the Sun in your birth chart in relation to that in another is symbolically significant.
Sign compatibility in the ancient tradition of astrology is not so simple. Unless your birth chart has Leo rising the Sun is not your chart ruler. The planet that rules your ascendant or rising sign is always the most significant. If in addition the Sun in your birth chart is in a cadent house, does not strongly aspect any planet and your chart has no Leo emphasis, then the Sun in your chart is not a significant factor.
Astrologers look more at the rising sign and its ruler, and the descendant and its ruler. Suppose your ascendant is Virgo. Your chart ruler is then Mercury. The sign of Pisces will be on your descendant. Pisces, in the tradition, is ruled by Jupiter. Now we look to see where Jupiter is placed in your birth chart. Suppose it is in your 1st house (close to your ascendant) or close to your chart ruler Mercury. You want Jupiter close to you! Suppose Jupiter is in your 4th house. The 4th house represents home and family. You want Jupiter at home with you! So your compatibility is likely to be good with someone who has Jupiter prominent in their birth chart. This could be by way of having Sagittarius or Pisces rising, an emphasis on those two signs in their chart or Jupiter in an angular house. Sun sign compatibility between the two charts will be less significant.
Next, consider someone who has the Moon and water signs prominent. Say Cancer rising with Moon in Pisces. Water spills unless it is in a container, so such a person may be attracted to someone with an earthy chart, or even a prominent Saturn if that planet is well placed by sign and house. This will be more important than Sun sign compatibility.

Aquarius

Aries

Cancer

Capicorn

Gemini

Leo

Libra

Pices

Sagitarious

Scorpio

Taurus

Virgo






