本研究採用產業和人力資源觀點，調查臺灣媒體代理商企劃人員工作內容擴大化的原因和影響，及公司和從業人員的因應方法。研究方法採用訪談及問卷調查法。訪談部分包括七位媒體代理商和三位廣告代理商中、高階主管。問卷調查回收來自廣告企業主、媒體、媒體代理商、廣告代理商89位從業人員的回答。結果發現，媒體代理商企劃人員工作擴大化是時勢所趨，服務內容從以媒體相關的服務爲主，延伸到產業環境趨勢資訊的提供與消費者行爲分析。「廣告主的要求」及「媒體多元化」是促成擴大化的原因。「廣告代理商」與「媒體代理商」從上下游垂直關係轉爲「競合關係」。「廣告企業主」是媒體代理商工作內容擴大化最直接有利的受惠者，對媒體企劃的表現表示肯定。媒體代理商對於企劃人員可以提供更多的職訓、輪調機會、適時的支持和協助。企劃人員本身需了解個人的欠缺，主動學習，抱持開放不自我設限的正面態度。

The study attempts to examine the antecedents and consequences of the job-enlargement of the planning staff in the media agencies and to discuss how managers and the staff can respond to the trend of the job-enlargement. The research interviewed seven managers working in the media agencies and three managers from the advertising agencies. In the second stage, questionnaires were distributed in the four relevant industries: the advertiser, the media, the media agency, and the advertising agency, and 89 staff members answered the questionnaire. The results show that job-enlargement of the planning staff in the media agencies is becoming the trend. The tasks of the planning staff primarily focus on services related to the media industry, and are further required to provide trend information about various industry environments and analyses of consumer behaviors. The job-enlargement of the planning staff in the media agencies primarily results from the advertiser's requirements and the plural development of the media. The relationships between the media agency and the advertising agency are changing from vertical channel partners to horizontal competitors. The advertisers benefit the most from the job-enlargement and are satisfied with the performance of the planning staff. The media agencies may provide more training, rotation opportunities, support and assistance for the planning staff. The planning staff needs to identify their weakness and improve it by active learning, and also to cultivate open-minded and positive attitudes toward their jobs.