易經初學者怎麼開始：從陰陽、八卦到六十四卦
作者：Wei Chun Chuang・2026-10-15
《易經》常讓人覺得艱深，其實它的結構非常有規律：兩種線條組成八個三畫卦，八卦兩兩相疊成六十四卦。只要照這個順序學，初學者就能看懂一個卦是怎麼組成的。這篇用最基本的概念，帶你走完第一步。
易經是什麼書？
《易經》一般指《周易》，分成「經」與「傳」兩部分。「經」是六十四卦的卦畫、卦名、卦辭與爻辭；「傳」是後人解釋經文的十篇文字，合稱「十翼」，例如〈彖傳〉、〈象傳〉、〈繫辭傳〉。
初學時先讀懂經的結構，再慢慢參看傳的解釋，比較不容易迷路。
陰爻和陽爻怎麼分？
易經最小的單位是「爻」。一條連續的直線「⚊」是陽爻，一條中間斷開的線「⚋」是陰爻。
陰陽不是好壞之分，而是一組相對的概念：剛與柔、動與靜、明與暗。讀卦時，先看每一爻是陰是陽，這是所有理解的起點。
八卦是怎麼來的？
把三條爻由下往上疊起來，每一條都有陰、陽兩種可能，一共能組出八種，這就是八卦（2×2×2＝8）。每個卦都有名稱與常見的象徵：
- 乾 ☰：天
- 坤 ☷：地
- 震 ☳：雷
- 巽 ☴：風
- 坎 ☵：水
- 離 ☲：火
- 艮 ☶：山
- 兌 ☱：澤
建議先把八卦的符號和象徵記熟，因為之後的六十四卦都是由它們組成的。
六十四卦怎麼組成？
把兩個八卦上下相疊，就得到一個六畫的卦。八乘八，共有六十四卦。下面三爻叫下卦（內卦），上面三爻叫上卦（外卦）。
例如上卦是坎（水）、下卦是離（火），就是「水火既濟」；反過來上離下坎，就是「火水未濟」，也就是六十四卦的最後一卦。許多卦的全稱，正是把上下兩卦的象徵加上卦名組合而成。
一個卦要從哪裡讀起？
六爻的順序是由下往上數：最下面是初爻，往上依序是二、三、四、五爻，最上面是上爻。陽爻稱「九」，陰爻稱「六」，所以「初九」是指最下面那一爻是陽爻，「上六」是指最上面那一爻是陰爻。
每個卦先有一段總說的卦辭，再有六段分別說明各爻的爻辭；乾、坤兩卦另外多了「用九」與「用六」。
初學者建議的學習順序是什麼？
- 分清陰爻與陽爻。
- 記熟八卦的符號與象徵。
- 練習把六十四卦拆成上下兩個八卦。
- 讀卦辭，掌握一卦的大意。
- 讀爻辭，觀察六爻由下到上的變化。
- 有餘力時，參看〈彖傳〉、〈象傳〉的解釋。
每天讀一卦就很夠了。重點不是背下所有文字，而是看懂結構，讓每一卦都拆得開、說得出來。
常見問題
- 學易經一定要會占卦嗎？
- 不用。易經可以當成一本經典來讀，先理解陰陽、八卦與卦爻的結構。起卦只是接觸卦的一種方式，適合當作自我反思的練習，而不是讓結果替你做決定。
- 六十四卦要全部背起來嗎？
- 不必一次背完。先熟悉八卦，就能把任何一卦拆成上下兩部分理解；卦名和卦辭可以在反覆閱讀中自然記住。
- 易經和八卦是一樣的東西嗎？
- 八卦是易經的基本元件。易經的主體是由八卦兩兩相疊而成的六十四卦，以及解釋這些卦的文字。
想用 App 練習？
想按部就班練習的話，易見是一款從零學易經的 iPhone App：八堂互動入門課（前三堂免費），六十四卦都有圖解導讀與小測驗，並有複習排程和錯題本。App 裡的起卦是練習功能，用來反思，不替你下結論。
How to start learning the I Ching: from yin and yang to the eight trigrams and sixty-four hexagrams
作者：Wei Chun Chuang・2026-10-15
The I Ching (Book of Changes) can look intimidating, but its structure is very regular: two kinds of line form eight three-line trigrams, and pairs of trigrams stacked together form sixty-four hexagrams. If you learn in that order, you can soon see how any hexagram is built. This article walks you through the first steps.
易經是什麼書？
"I Ching" usually refers to the Zhou Yi, which has two parts: the classic and the commentaries. The classic contains the sixty-four hexagram figures, their names, the judgment for each hexagram and the statements for each line. The commentaries are ten later texts explaining the classic, known together as the "Ten Wings", such as the Tuan, the Xiang and the Great Commentary (Xici).
Beginners do best by understanding the structure of the classic first and consulting the commentaries gradually.
How do you tell a yin line from a yang line?
The smallest unit is the line. A solid line "⚊" is yang; a broken line "⚋" is yin.
Yin and yang are not good and bad. They are a pair of relative ideas: firm and yielding, moving and still, bright and dark. Seeing whether each line is yin or yang is where every reading begins.
Where do the eight trigrams come from?
Stack three lines from the bottom up. Each line can be yin or yang, so there are eight combinations (2×2×2 = 8): the eight trigrams. Each has a name and a familiar image:
- 乾 ☰：天
- 坤 ☷：地
- 震 ☳：雷
- 巽 ☴：風
- 坎 ☵：水
- 離 ☲：火
- 艮 ☶：山
- 兌 ☱：澤
Learn these symbols and images well, because every one of the sixty-four hexagrams is made from them.
六十四卦怎麼組成？
Put one trigram on top of another and you get a six-line hexagram. Eight times eight gives sixty-four. The bottom three lines are the lower (inner) trigram; the top three are the upper (outer) trigram.
For example, Water (Kan) above Fire (Li) is "After Completion" (Ji Ji); turn it around, Fire above Water, and you get "Before Completion" (Wei Ji), the last of the sixty-four. Many full hexagram names simply combine the images of the two trigrams with the hexagram's name.
Where do you start reading a hexagram?
Lines are counted from the bottom up: the first (bottom) line, then lines two to five, and the top line. Yang lines are called "nine" and yin lines "six", so "first nine" means the bottom line is yang and "top six" means the top line is yin.
Each hexagram has one judgment for the whole figure, followed by six line statements. Qian and Kun each have one extra statement, "using nines" and "using sixes".
What is a good learning order for beginners?
- Tell yin lines from yang lines.
- Learn the symbols and images of the eight trigrams.
- Practise splitting each hexagram into its upper and lower trigrams.
- Read the judgment to grasp the overall idea.
- Read the line statements and notice how the situation changes from bottom to top.
- When you are ready, consult the Tuan and Xiang commentaries.
One hexagram a day is plenty. The goal is not to memorise every word but to understand the structure, so that you can take any hexagram apart and explain it.
常見問題
- Do I need to cast hexagrams to learn the I Ching?
- No. You can read the I Ching as a classic text and start with yin and yang, the trigrams and the line structure. Casting is one way to meet a hexagram, best used as a prompt for self-reflection rather than something that makes decisions for you.
- Do I have to memorise all sixty-four hexagrams?
- Not all at once. Once you know the eight trigrams, you can understand any hexagram as an upper and a lower half; names and judgments stick naturally with repeated reading.
- Are the I Ching and the eight trigrams the same thing?
- The trigrams are the building blocks. The body of the I Ching is the sixty-four hexagrams formed from pairs of trigrams, together with the texts that explain them.
Practise with an app
If you want structured practice, YiJian is an iPhone course that teaches the I Ching from zero: eight interactive beginner lessons (the first three free), guided reading of all sixty-four hexagrams with diagrams and quizzes, plus spaced review and a mistakes notebook. Casting in the app is a practice feature for reflection; it does not hand you conclusions.