b<-boxplot(metals[,-1],
                xaxt="n",border = "white",col = "black",
                boxwex = 0.3,medlwd=1,whiskcol="black",
                staplecol="black",outcol="red",cex=0.3,outpch=19,
                main="Summary of metal concentrations by Site")
axis(side=1,at=1:length(b$names),
                labels=paste(b$names,"\n(n=",b$n,")",sep=""),
                mgp=c(3,2,0))#mpg:轴标题，轴标签，轴线，The default is 'c(3, 1,0)'
lines(b$stats[3,]~c(1:dim(metals[,-1])[2]))

非常感谢，能上传一下这个数据的内容，他是怎么整理的，这样我才能做出来，

论坛不支持csv格式，你自己读这个txt的吧

b<-boxplot(metals[,-1],
                xaxt="n",border = "white",col = "black",
                boxwex = 0.3,medlwd=1,whiskcol="black",
                staplecol="black",outcol="red",cex=0.3,outpch=19,
                main="Summary of metal concentrations by Site")
axis(side=1,at=1:length(b$names),
                labels=paste(b$names,"\n(n=",b$n,")",sep=""),
                mgp=c(3,2,0))#mpg:轴标题，轴标签，轴线，The default is 'c(3, 1,0)'
lines(b$stats[3,]~c(1:dim(metals[,-1])[2]))

tks~~~~~~~~~~~~