Abstract: Salvia splendens is used widely in landscape. It will be hot summer in Beijing when the Olympic Game opens in August 2008. Using heat tolerant varieties is one of the effective measures. The chlorophyll content, conductivity, malondialdehyde and proline content of 5 varieties of Salvia splendens such as 1120#, 12#, 73# and two introduced varieties Vista and Scarlet Queen under the heat stress were investigated. The results showed that as the heat treatment prolonged, the varieties Vista and Scarlet Queen’s chlorophyll content drop fastest, cell membrane injury rate went up fastest, MDA content was the highest, proline content increase was the smallest. Therefore they were both not heat tolerant varieties, while varieties 1120#, 12# and 73# we bred have better heat tolerance than the introduced varieties. And the difference between our varieties and introduced varieties was proved in the potted flower production in the summer of Beijing. So varieties 1120#, 12# and 73# were suggested when grow Salvia splendens in hot summer.