Abstract: Introducing convenient transportation and informational proximity to extend the dimensions of proximity, and employing the panel data from high-tech industries of 31 Chinese provinces in 1995-2010, this paper examines the effects on inter-regional knowledge spillovers of geographical proximity, informational proximity, convenient transportation degree and combined proximities by spatial panel data analysis. The empirical results indicate that positive spatial autocorrelation is significantly and strengthened. Second，R＆D capital contributes more than R＆D labor on knowledge production. Third, under all dimensions of proximities except informational proximity discussed in the paper，the presence of Chinese inter-provincial knowledge spillovers in high-tech industries is much evident. Fourth, under the single dimension of proximity, geographical proximity make somewhat higher effects on inter-regional knowledge spillovers than other proximity does. But the effects under informational and convenient transportation combined proximity indicate that the geographical will be no longer the main restrictive factor for development. Fifth, combined proximity does not behavior as prediction in that it can’t promote inter-regional knowledge spillovers much more. At the end of the paper, we discuss the implications and give some suggestions.