Errors, as a part of foreign language learning process, are natural, inevitable and necessary. It shows that the learners are in the transitional stage of grasping the target language. However, we should identify the cause and analyze the errors timely and accurately, so that we can solve the problem and the students will not repeat the same mistake.
The paper concentrates on ninety compositions of thirty Korean learners of Chinese at higher and middle levels. The methods of Contractive Analysis, Error Analysis and the theory on Inter-language in second language teaching are adopted in this paper so as to sum up the types of errors with detailed analysis of the cause of their formation.
This paper maintains that the errors committed by Korean students can fit into the following three categories: error of omission, error of addition and error of word order.
Those errors, which are often seen in Korean students’ compositions, are caused by two main reasons: First, the negative transformation of the mother tongue. Chinese and Korean vary greatly, not only in basic word order but also in many other aspects. For example, there are a great number of quantifiers in Chinese and many nouns have their own unique quantifier, which must be properly used or will lead to errors. However, in Korean, there are also quantifiers, but nowhere near the number of Chinese. In many cases, the quantifiers can be omitted in Korean. Therefore the negative transformation of the mother tongue causes the error of omission in their compositions.
The second main reason: insufficient knowledge of Chinese distracts the learning of new grammatical rules. For example, those Korean learners of Chinese at higher and middle levels basically know that “Le”(Chinese aspectual particle), should be used after the verb, mainly showing the action is completed. Although in Chinese, “Le”(Chinese aspectual particle), a kind of grammatical symbol suffix, must be used flexibly. In some cases, it must be used and in other cases, it mustn’t. Korean students who have not fully grasped its usage will lead to this kind of abused errors.
Therefore, on one hand educators who teach Chinese as a foreign language must fully grasp Chinese grammatical rules and explain them comprehensively; On the other hand, they should also distinguish the similarities and differences between Korean and Chinese so that the errors can be corrected timely.

“偏?”是外????程中的一?部分，是?其自然的?象，是不可避免的，也是必需的，?表明??者正在?不?到掌握?言的?渡?段。但出?偏?之后，?及?、准?地?出偏?的原因?加以分析，才能?根本上解?偏???，?而使?生?不再重蹈覆?，出?同?的??。本?文以30名具有中高???水平的???生的90篇作文??料，?合第二?言???究中适用的?比分析、??分析及中介?理?,??生?的偏?分??漏、?加、?序三??型，??生?的偏??行了具?分析，?出了?致偏?的根由。
通?分析，?者?????生在作文?中最容易出?的偏?主要是?漏偏?、?加偏?及?序偏?。究其原因，主要有以下?点：第一，母???移的影?。?????不?在基本?序上存在差?，而且在其他?多方面都有不同之?。比如，在??中，量?十分??，?多名?都有自己特有的量?，若在此?使用其他量?，?容易出?偏?。而在??中，?然也有量?，但其?量?不及??量?多，且在?多情?下可以省略，因此，受母???移的影?，?多?生?在作文?中漏掉量?而出??漏偏?。第二，已?掌握的不完全的??知????新的?法?象的干?。例如，??水平?到中高?的???生基本上都知道“了”作???助??，用在??后，主要表示?作的完成。但是??中的“了”?是一??有?法?志性的?尾，但?不是完全意?上的?志，使用起?有?大的?活性，有?候一定要用，有?候一定不能用。???生由于?有完全掌握其用法，?果??致?用不用、不?用而?用的偏??象。
因此，?就要求?事??????的?育者一方面要全面掌握???法，做到?解全面、周到；?一方面也要掌握?????的?同之?，以便?生在出?母???移?及??予?正。