摘 要 法人說明會是近年公司管理當局對投資人之重要溝通管道，提高企業資訊透明度及降低企業內部人與外部人的資訊不對稱。藉由法人說明會的召開，管理當局與投資人間的溝通互動較為直接，資訊的揭露亦較為即時。 此即是本研究的重點：法人說明會召開對於產品多角化績效的影響。以台灣經濟新報(TEJ)資料庫中2008-2013年台灣上市上櫃公司為觀察樣本。實證結果發現(1)法人說明會的召開(2)法人說明會的召開次數均能夠提高產品多角化的績效，增加公司的價值，並且顯示(3)經常性召開法人說明會的公司，其產品多角化的績效較佳。 ;ABSTRACT In recent years, firms tend to hold conference calls to have more communication with market investors so that to promote information transparency and to reduce the information asymmetry between insiders and outsiders. By holding conference calls, the communication and interaction between management and investors can be more direct and the disclosure of information. The primary objective of this paper is to study the effect of conference calls, self information disclosure, to firm and investors. This study examines the association among conference calls, product diversification on performance. Using a sample of publicly traded firms listed on the Taiwan Stock Exchange from 2008 to 2013, we find that to hold and number of conference calls would positively moderate effect on the relationship of product diversification on performance. The results also show that the frequency of conference calls becomes higher, the performance of product diversification becomes higher.