Purpose: This study was intended to analyze and examine the overall research trends about an art-therapy mainly with clay to verify the effectiveness of individual studies thereon, and by which to provide basic materials being useful in composing and operating objective and effective programs in utilizing clay for the art-therapy in the future. Method: The research trends were analyzed on 91 these and academic journals relating to the art-therapy mainly with clay, which were published in South Korea from 1994 to March 2016, and those theses and academic journals were analyzed using technical statistics with frequency and percentage. Further, 28 of them were classified separately and analyzed using a professional meta-analysis program, CMA(Comprehensive Meta Analysis)3.0. Moreover, those were analyzed using Q statistic of CMA, in order to figure out meaningful differences among related variables. Results: According to the overall research trends about the art-therapy mainly with clay medium, the general trend was as follows: the preliminary targets were children; the single target therapy and the group target therapy were performed on them for recovering psychological health; and the art-therapy was conducted 31~60 minutes per session and totally 16-20 sessions. According to the results verifying the effectiveness using meta-analysis, the greatest effect appeared in case of targeting the group of 7 or less infants, aiming at self-development, and conducting it 91-120 minutes per session and totally 16-20 sessions. Discussions and Conclusion: It is expected that more effective programs for a variety of objects would be developed considering the characteristics of researchers and the subjects of researches in composing the art-therapy program mainly with clay in the future, and the follow-up studies which verify the effectiveness on the therapeutic factors of clay would be conducted.