相位是什麼？合相、對分、三分、四分、六分怎麼看

What are aspects in a birth chart?

作者：Wei Chun Chuang・2026-10-24

Once you know which sign and house each planet falls in, the next layer is aspects. The lines drawn across the middle of a chart wheel are aspects, and what they describe is an angular relationship between two points. This article covers how aspects are measured, which ones there are, what an orb is, and where a beginner should start.

What does aspect mean?

An aspect is an angular distance between two points, measured along the ecliptic. The ecliptic is the path the Sun traces through the sky over a year, and a chart flattens it into a 360-degree circle. Subtract the two points' ecliptic longitudes, take the smaller way round, and that is how far apart they are. When that figure lands near certain values, the two points are said to be in aspect.

Note that this measures a difference in ecliptic longitude, not the real distance between two bodies in the sky, and it ignores how far north or south of the ecliptic either one sits.

五個托勒密相位

The five angles Ptolemy set out in the Tetrabiblos are still the standard working set:

1. Conjunction (0°): the two points sit at almost the same degree, traditionally read as two forces blended together.
2. Sextile (60°): one sixth of the circle apart.
3. Square (90°): one quarter of the circle apart.
4. Trine (120°): one third of the circle apart.
5. Opposition (180°): facing each other across the wheel.

Later writers added many minor aspects, among them 45°, 135° and 150°, but those are an advanced topic. The five above are enough to start with.

容許度是什麼？

Real charts almost never produce exactly 90.00 degrees, so each aspect is allowed a margin of error called an orb. With a 6-degree orb, anything from 84 to 96 degrees counts as a square, and the closer to the exact angle, the tighter the aspect is generally considered to be.

There is no agreed standard orb; it is a convention, and it differs between astrologers. A common modern habit is 6 to 8 degrees for the five major aspects, only 2 to 3 for minor ones, and wider orbs for the Sun and the Moon than for other planets. Classical authors such as William Lilly used a different scheme, assigning orbs to the planets themselves, which does not match the defaults in modern software. So when you read someone else's chart, ask which set of orbs they used.

Soft and hard aspects

Traditionally the sextile and trine are grouped as soft aspects, the square and opposition as hard ones, while a conjunction depends on the two points involved. Modern practice generally reads that hardness as two needs pulling against each other and requiring effort to coordinate, rather than as misfortune or punishment; soft aspects run more easily and are, for that reason, easy to overlook. This site treats the grouping as language for describing tension, not as a way to predict whether events will go well or badly.

An aspect always connects two specific points

An aspect on its own carries no meaning; the meaning lies in the pair it connects. There is no free-floating square, only Moon square Saturn or Venus square Mars. So read the two points together: what each one stands for, which sign and house it occupies, and then what the angle adds to the relationship. Remembering only that squares mean pressure, without looking at which two points are involved, is half a reading.

Which aspects need an exact birth time?

Aspects between planets are not very sensitive to the time, because a planet covers only so many degrees in a day; being an hour or two out rarely makes an aspect disappear. The Ascendant and Midheaven, however, move roughly a degree every four minutes, so any aspect involving them depends entirely on an accurate birth time. If the time is uncertain, draw no conclusions from that group.

How should a beginner start?

You do not need to read every line in the wheel at once. A workable order:

• Look only for aspects to the Sun, the Moon and the Ascendant first.
• Among those, pick the ones closest to the exact angle, that is, the tightest ones inside your orb.
• Write one sentence for each: which two points, which angle, and how the things each of them cares about tug on the other.

Widen out to the other planets once that feels familiar. Aspects are a way to describe the internal tension of one chart, not a tool for pronouncing on fortune.

常見問題

Which orb size is correct?

There is no single right answer. Orbs are a convention each astrologer sets, commonly 6 to 8 degrees for the major aspects, 2 to 3 for minor ones, and wider for the Sun and Moon. What matters is using one consistent rule across the chart rather than widening it to produce an aspect you hoped to find.

四分相和對分相是壞事嗎？

Traditional texts group them as hard aspects. Modern practice usually reads that hardness as two drives needing to be coordinated, not as misfortune. This site treats aspects as language for describing tension, not as a way to predict good or bad outcomes.

不知道確切出生時間，相位還能看嗎？

Most planet-to-planet aspects still hold, because planets move only so far in a day. Aspects involving the Ascendant or Midheaven change a great deal with the time, so set those aside until the birth time is confirmed.

Practise on your own chart

To see the aspects in your own chart, use the Shilai Astrology web version: free, no sign-up and no login, it draws your natal chart and comes with 36 lessons, aspects among them. There is also an iPhone app, 時來－星座, which is still in development, not yet released and not available to download.

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