Sorry my mistake, it was 100,000 civilians died. Much higher number injured, obviously. 
Sino-Vietnamese War - Wikipedia, the free encyclopedia
What the PLA Learned in Vietnam, 1979
Some Chinese soldiers called it a “painful, little war.” Vietnamese troops avoided battle and instead harassed PLA forces. Some Chinese officers described it as a “ghost war,” since the enemy troops were almost invisible, or a “shadow war,” since it seemed they were fighting against their own shadows. The Vietnamese troops employed the same tactics, made the same moves, and used the same weapons as the Chinese.
They knew exactly what the Chinese were trying to do. They exploited almost every problem and weakness the Chinese had. The Chinese troops had to fight their own problems first before they could fight the Vietnamese. Deng’s border war taught the PLA a hard lesson….
Many of the PLA’s commanding officers were shocked by the poor discipline, low morale, combat ineffectiveness, and high casualties in the 1979 Sino-Vietnamese War. During the nineteen days of the first two phases, the PLA suffered 26,000 casualties, about 1,350 per day. Gerald Segal points out that in Vietnam, “in contrast to Korea, Chinese troops performed poorly. In Korea, they adequately defended North Korea, but in 1979 they failed to punish Vietnam. China’s Cambodian allies were relegated to a sideshow along the Thai frontier, and China was unable to help them break out.”
During the war, 37,300 Vietnamese troops were killed, and 2,300 were captured.
The Soviet Union surprised the Vietnamese by refusing to get involved in the conflict. On February 18, Moscow had denounced China’s aggression and promised that the Soviet Union would keep its commitments according to the Soviet-Vietnam cooperation and friendship treaty. Then, however, the Soviet Union did not make any major moves. Russian military intelligence did increase its reconnaissance planes and ships in the South China Sea and along the Vietnamese coast after China’s invasion. On February 24, two Russian transport planes landed at Hanoi and unloaded some military equipment. Most countries maintained a neutral position during the Sino-Vietnamese War.
The brief war was a grievous misfortune for both China and Vietnam, not only because it resulted in material and human losses for both nations but also because it brought years of earlier cooperation to a dispiriting conclusion. The war showed that American belief in the domino theory was misplaced, since two Communist countries, one of which had just attained national liberation, were now in conflict with each other. Each valued its own national interests much more than the common Communist ideology. On February 27, 1979, Deng told American journalists in Beijing that “Vietnam claims itself as the third military superpower in the world. We are eliminating this myth. That’s all we want, no other purpose. We don’t want their territory. We make them to understand that they can’t do whatever they want to all the times.”
Hanoi believed, however, that the Vietnamese army had taught the Chinese army a lesson. One [People's Army of Vietnam] general said that China lost militarily and beat a hasty retreat:
“After we defeated them we gave them the red carpet to leave Vietnam.” As Henry J. Kenny points out, “Most Western writers agree that Vietnam had indeed outperformed the PLA on the battlefield, but say that with the seizure of Lang Son, the PLA was poised to move into the militarily more hospitable terrain of the Red River Delta, and thence to Hanoi.” Kenny, however, points out that Lang Son is less than twelve miles from the Chinese border but is twice that distance from the delta. Moreover, at least five PAVN divisions remained poised for a counterattack in the delta, and thirty thousand additional PAVN troops from Cambodia, along with several regiments from Laos, were moving to their support.
Thus the PLA would have taken huge losses in any southward move toward Hanoi.
http://http://faroutliers.wordpress.com/2009/02/04/what-the-pla-learned-in-vietnam-1979/
