这两者之间的界限在各个国家估计会有些差异吧。

Erotic and pornographic mean quite different things in English, but in a different paradigm of thinking this difference is not captured. For example, erotic can mean sensual, arousing, sexy, but without the negative connotation of "pornographic". In literature, pornography (黄色书籍，色情书籍，成人书籍）has been long frowned upon both in the west and in China (subject to 扫黄运动，anti-pornograhy campaign). However, erotica, which has been increasingly accepted, does not have the vulgarity that pornography often implies, and is translated either into 性感文学 or 情趣文学。Thus in broad terms you can translate erotic into 性感，or its euphemism in China, 情趣，while pornographic is 色情，淫秽 or 黄色。

感觉中文传统上是用‘性爱的’表示‘被公共道德所接受的关于性的内容‘，没有贬义。而用’色情的‘来指’不为公共道德所接受的关于性的内容‘，有贬义。这似乎很接近erotic与pornographic的区别。

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Note added at 21 hrs (2013-03-30 02:38:05 GMT)
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不错

Erotic 以情為重，所以是情色.
Pornographic 以色為重，所以是色情.

這是我個人喜歡的譯法,，不過豆瓣裡也提到「情色」這詞近代才有，所以不一定樣樣場合適用。