Morphophysiological characters associated with yield in warm climate area can be used to determine heat stress tolerance characters. Correlation and path coefficient analysis were used to ascertain the relationship between morphophysiological characters and yield, and to estimate direct effects as well as indirect effects on them. Nine cultivars were evaluated in Garut, Indonesia which is situated at an altitude of 732 masl with an average air temperature of 28°C at noon and 23°C at night. Randomized complete block design was used in this experiment and it was performed in triplicate. As the result, correlation analysis indicated that plant height, leaf number, leaf area index, stomatal density, dry weight, tuber number, and tuber diameter showed positive relationship with yield, whereas chlorophyll content showed negative relationship with yield. Furthermore, path coefficient analysis indicated that plant height, leaf number, leaf area index, tuber number, and tuber diameter showed positive direct effect on yield. Path coefficient analysis also indicated indirect effects among characters. Plant height had positive indirect effect on yield through leaf number and leaf area index. Leaf number had positive indirect effect on yield through leaf area index, tuber number, and tuber diameter. Tuber number had positive indirect effect on yield through tuber diameter.