This study analyzes 197 companies formed through strategic alliance during the period 1995-2004. There are 107 samples of technological strategic alliance and 90 samples of marketing strategic alliance. The empirical methodology used in this research is the event study approach, which assesses the value implications of the announcement of forming strategic alliance. This study then examines relationships between abnormal returns and relative scale of strategic alliances partners, and profitability of companies through regression analysis to find the following results: 1. The announcement will bring significantly positive abnormal return to the company. 2. Abnormal returns of technological alliance are greater than that of marketing alliance announcements. 3. There is no significant relationship between relative sizes of partners and abnormal returns. Accumulative abnormal returns of relatively larger size partner are higher than relatively smaller size partners. Relatively larger partners in technological alliances gain more benefits in a strategic alliance. 4. The profitability of firms entering strategic alliances is negatively correlated with abnormal returns attributable to alliance announcements. Such a negative correlation is greater for marketing alliances than for technological alliances.